To copy a file or folder

1.	Open My Documents If the file or folder you want to copy is not located in My Documents or its subfolders, use Search to find it. To open Search, click Start, and then click Search.
2.	Click the file or folder you want to copy.
3.	Under File and Folder Tasks, click Copy this file or Copy this folder.
4.	In Copy Items, select the drive or folder you want to copy to, and then click Copy.

Note

•	To open My Documents, click Start, and then click My Documents.
•	You can copy more than one file or folder at a time.
•	To select consecutive files or folders, click the first item, press and hold down SHIFT, and then click the last item. To select nonconsecutive files or folders, press and hold down CTRL, and then click each item.

To rename a series of files

1.	Open My Documents If the series of files you want to rename is not located in My Documents or its subfolders, use Search to find it. To open Search, click Start, and then click Search.
2.	Select the files you want to rename.
3.	On the File menu, click Rename.
4.	Type the new name, and then press ENTER. All of the files in the series will be named in sequence using the new name you type. For example, if you type Birthday, the other files in the series will be named Birthday (1), Birthday (2), and so on.

Note

•	To open My Documents, click Start, and then click My Documents.
•	To select consecutive files or folders, click the first item, press and hold down SHIFT, and then click the last item. To select nonconsecutive files or folders, press and hold down CTRL, and then click each item.
•	To specify the starting number for the series, type the starting number in parenthesis after the new file name. The files in the series will be numbered in sequence starting with the number you type. For example, if you type Birthday (10), the other files will be named Birthday (11), Birthday (12), and so on.

To move a file or folder

1.	Open My Documents If the file or folder you want to move is not located in My Documents or its subfolders, use Search to find it. To open Search, click Start, and then click Search.
2.	Click the file or folder you want to move.
3.	Under File and Folder Tasks, click Move this file or Move this folder.
4.	In Move Items, click the new location for the file or folder, and then click Move.

Note

•	To open My Documents, click Start, and then click My Documents.
•	To select a consecutive group of files, click the first file, press and hold down SHIFT, and then click the last file. To select files or folders in nonconsecutive order, press and hold down CTRL, and then click the items you want.
•	You can also move a file or folder by dragging it to the desired location. For more information, click Related Topics.

To save a file

1.	On the File menu of the program you are working in, click Save.
2.	If you haven't saved your file before, type a name for the file in File name.

Note

•	To save a copy of a file under a different name or in a different location, on the File menu, click Save As. Click the Save in arrow to find the drive or folder where you want to save the file, and then type the new name in the File name box.

To open a file or folder

1.	Open My Documents If the file or folder you want to open is not located in My Documents or its subfolders, use Search to find it. To open Search, click Start, and then click Search.
2.	Double-click the file or folder you want to open.

Note

•	To open My Documents, click Start, and then click My Documents.
•	If the file you want to open is not associated with a particular program, you can select one. To do so, right-click the file, click Open With, and then select the name of the program.
•	You can use the View menu to change the way files are displayed. You can also use the View tab in the Folder Options dialog box to change file and folder settings. To open the Folder Options dialog box, on the Tools menu, click Folder Options.

To create a new folder

1.	Open My Documents
2.	Under File and Folder Tasks, click Make a new folder. A new folder is displayed with the default name, New Folder, selected.
3.	Type a name for the new folder, and then press ENTER.

Note

•	To open My Documents, click Start, and then click My Documents.
•	You can also create a new folder by right-clicking a blank area in a folder window or on the desktop, pointing to New, and then clicking Folder.

Windows Xp Registry Clean Up Utility

The registry is the place where your computer stores the configuration information about your computer and your installed programs so that your operating system can use them. Maintaining the registry is an important step in keeping your computer healthy.

Registry Mechanic is not only the most popular registry cleaner on the market (with 100000+ downloads per week) but also one of the easiest to use! With Registry Mechanic you can safely clean and repair Windows registry problems with a few simple mouse clicks! Problems with the Windows registry are a common cause of Windows crashes and error messages. R Before we get into the details of registry cleaners, let's cover just a little information concerning how your computer runs and why it slows down over time. Don't worry ... this will only include the basics! If you're running any version of Windows on your computer, then you have a Windows registry. This Windows Registry is where all the information about your computer is stored. The registry includes installation data about the software you run and all of your computer's preferences, settings, and registry keys. Pretty much everything about your computer is filed away in the Windows registry. Scan at free download on registry cleaners. This information includes data pertaining to all the programs hardware and user permissions on the system Why a registry cleaner important? Registry cleaners are important because it protects your PC from other processes that are not considered viruses, but can be harmful to your PC. Is your computer slowing down without your knowledge? Are you having errors that are not distinguished by your anti-virus program? Your PC might be affected by applications that are running without your knowledge. Registry cleaners are a must! This means that the system begins looking for information from the beginning of the registry and goes through each entry individually. Free scan at registry cleaner f r windows xp home download. This gradually clutters and fragments the registry over time. Take Your Pick There are many registry cleaners on the Internet. What is the Windows Registry? Well as the name suggests, it is a critical registry of programs and settings that are stored on your computer. You can find the registry by running regedit from a command prompt (Start -> Run -> type regedit -> OK). Now be careful! Do not make any changes. Just back out slowly.Indeed changes made manually in the registry by people not knowing exactly what they are doing are the source of many a computer error. Even experts fear to tread into the registry and that is why specialist software exists to repair registry errors.

Download Free Pc Fix ...

Download Free Pc Fix Registry Cleaner

The registry is the place where your computer stores the configuration information about your computer and your installed programs so that your operating system can use them. Maintaining the registry is an important step in keeping your computer healthy.

If your computer is running slow and even shutting down out of the blue you should check out websites out there which feature a free scanner that can track down evil program lurking on your hard drive and protect you from possible future malicious attacks on your system. The registry cleaner scans the registry for information that does not need to be on the system but is there nevertheless.

This slows the system down every time the registry is scanned for information that is needed to run the system. The scan always starts from the beginning of the registry and continues until the data is found. The scan will include going through all the entries including the bad entries that serve no purpose to the system.

There are tens of thousands of such entries. Going through each one slows the system greatly. Registry cleaner software removes these entries and then compacts the registry by filling in the spaces left by removing the useless data. This is how a registry cleaner speeds up a system. Scan at registry windows xp service pack. Once the problem is identified the software technology easily cleans the registry

Take Your Pick There are many registry cleaners on the Internet. You could download a trial or a free version of one of the windows registry cleaner software and run it on your system to see how efficient it will make your computer. The installation and operating of registry cleaner software such as a pc registry cleaner or the windows XP registry cleaner is very simple and takes just a few minutes to install.

The registry cleaner software scans your system registry for all redundant entries including broken links and removes them from the registry. Some registry cleaner utilities also search for malicious ActiveX components and clean them from the system registry leaving the registry more compressed and easy to read by the operating system. This in turn makes the registry more efficient and speeds up the entire system making it more comfortable for the user.

So if you have noticed that your computer is becoming more and more sluggish it may be the registry is getting filled with useless entries and needs to be cleaned with a registry cleaner. Go ahead and get yourself one from the Internet and try it out for yourself. You will not be disappointed. This permits the user to select the programs that start up automatically when the system boots. Free scan at vba replace default error message cell protected. This information includes data pertaining to all the programs hardware and user permissions on the system.

Here is when the Window registry cleaner steps in to do a thorough job of ridding the system of all the redundant data stored therein. Backup Copies With Backup

The steps to fix registry on computer is not as easy as 1-2-3. But it is not as complicated as fixing cars either. To fix registry on computer is to simply change the registry information back to its default setting or to repair any errors incurred therein.

Whether it is complicated or relatively easy to fix registry on computer, the fact remains the same: you have to do backups.
Backups are extremely important so that you can still retrieve your date in case you have failed to fix registry on computer. Also, it enables you to always restore the default settings of the registry of your computer in case you were not able to fix it.

See http://www.registry-cleaners-reviewed.info/registry-cleaners/registry-cleaner-download-mechanic-windows-installation.php. One way to fix registry on computer is to have a backup for your Registry Checker

How Internet has affected...

How Internet has affected the Work from Home Businesses

The internet has revolutionized every thing. The way the people work is also not unaffected from the use of World Wide Web. It takes care of every thing right from entertainment to earning money. Due to popularity of internet the concept of work from home has gained more impetus. It is always a good idea to work from home. Especially for women, who likes to perform their daily domestic tasks and also like to make money? There are different areas in which work from home can be started. But merely deciding to start work from home does not solve all the problems. There are certain issues that need to be addressed before you go ahead and start the work from home.

The internet has revolutionized every thing. The way the people work is also not unaffected from the use of World Wide Web. It takes care of every thing right from entertainment to earning money. Due to popularity of internet the concept of work from home has gained more impetus. It is always a good idea to work from home. Especially for women, who likes to perform their daily domestic tasks and also like to make money? There are different areas in which work from home can be started. But merely deciding to start work from home does not solve all the problems. There are certain issues that need to be addressed before you go ahead and start the work from home. For any person who wishes of starting work from home should first have the basic knowledge of the route through which he can get paid and bring the money to his or her bank account. Work from home can be started with the use of internet; this means that whole world is now your client. So you need to have a method by which you can transfer the funds in different currencies to your bank account. There are websites that will do this for you. Also they secure you from fraud as you need not give the parties your bank account number etc. Once your work from home channel is clear you need to think on the area in which you can work. There are different fields in which the work from home can be started. You can start with the search engine optimization area. This is a very potent area since the numbers of websites that are popping up are enormous. Since every website needs to make it to the top in the search engines, this job is in high demand. Other area of interest for people willing to work from home is the marketing area. Online marketing has become the trend of the time. It gives more success and clients as compared to conventional marketing. There is a lot of scope in this field too. All you need to know is the methods and tools that are used for online marketing and get started. Companies require persons that are willing to devote time and efforts to promote their products through different forums and emails. You can be a part of the team and get started. Yet another area to start work from home is the Ecommerce. You can sell your own products on the internet. If you are smart enough you can also start online trading. With whole world at your door step you can trade products at a cheap rate from one part of the world and make them available at the other. Though this area needs some skills and initial investment, it can make a lot of money. For people who have some soft skills can get their work from home started with the help of websites that offer freelancing jobs. You can make use of your technical skills like website design, programming etc and make a lot of money.

Customized Jump Drives

Customized Jump Drives are the ideal way to store, transfer and keep the data handy. No software installation or drivers are required to use Custom Jump drives. For more information on customized jump drives, visit us at customjumpdrives.com.

Jump drives or USB drives have become very popular these days because they can be easily customized. Customizing jump drives means imprinting your company’s logo, Web addresses, your company’s slogan, or even a punch line. It’s an effective tool in getting your message across. Jump drives are also known as flash drives, keychain drives, disk on keys, or P-drives.

Being the typical plug-and-play portable storage devices, jump drivessimply use flash memory. Small in size, they easily fit on a key-chain, and are more prone to get lost. This can be risky enough because you lose any replicated data along with the drive, which can pass on to wrong hands.

Customized jumpdrives are about the size of a pack of gum and are used for various purposes such as storage of documents, pictures, work files, and even databases. They are easy to use. All you have to do is plug the device into a USB port. After plugging, the operating system recognizes the device as a removable storage disc and gives it a drive letter. Using this drive letter, you can access the customized jump drive just like you would access a floppy or CD.

With its increasing popularity, the availability of these jump drives in various size and style is also increasing. Now, you can find customized jumpdrives in various storage sizes ranging from 512K to 4 Gigabytes. This means you can stop using unreliable floppies and CDs. The disadvantage about these tiny, high capacities, portable jump drives lies in their small size. These smaller sized equipments are easier to lose. This may mean loss of confidential data. However, data loss can be prevented by using data replication software such as the Replicator. By downloading this free data replication software, you can protect your valuable data and information.

The data replication through Replicator happens in real time. Even backups are encrypted. So if you lose your customized jump drive, another person will not be able to replicate the data in any way. Before you buy one of these portable drives, download the Replicator software. If you wish to get your own customized jump drive, Lexar is the highest quality brand on the market.

Custom JumpDrives will customize your Lexar jump drive by imprinting your company name, logo, or Web address. Customized Lexar jump drives make the best corporate gift for your clients and customers. Giving customized jump drives is an effective marketing tool for merchandising, promotions, and corporate orientations. It also works as an employee appreciation gift. For more information on customized jump drives.

How to Really Install a Modem

Most motherboards now come with sound, video, and even networking built-in. But a modem is not usually built-in to a motherboard. This is because modem technology has been changing very rapidly. It is preferable to have the modem on an expansion card.


Most modem manuals assume that Plug and Play will automatically install the modem correctly, but this is rarely the case. Use the four steps described below to properly install a modem.



Step 1. Download the latest driver from the manufacturer's Web site.



Most modems come with an Installation CD. The problem with this is that the CD contains drivers for eight different operating systems and it usually tries to install the wrong one. Even if it does install the correct driver, its usually not the latest version. Also, the CD usually comes with several non-essential programs (AOL etc.) that the modem company earns commission on when you install them.



I admit, its difficult to download a driver before you install the modem. You may be replacing an old modem, or you may have another computer, or a friend with a computer with access to the Web.



Preferably, do this before you purchase the new modem. That way you can see what kind of driver and technical support is available for the modem before you shell out the cash.



Step 2. If you are replacing a modem, remove the old modem. First physically open the case and remove the old modem. Then start the computer and remove the modem in Control Panel. If the system is Windows 2000 you will have to login as Administrator. Open the Modems utility, select the name of the modem on the General tab. Then click on the Remove button.



Step 3. Install the new modem.


First physically install the new modem. If the system is Windows 2000 you will have to login as Administrator. Plug and Play may install the new modem for you, that means it found an old driver on your system and used that to install the modem. Or it may start the "Add New Hardware Wizard". Click on the Cancel button.



The "Add New Hardware Wizard" is rarely able to find the proper driver for a modem, and when the Wizard appears as the computer starts, it blocks your access to Explorer, so you can't use Explorer to locate a driver. Just click on the Cancel button to close the Wizard.



After Windows starts you can open the "Add New Hardware Wizard". The Wizard will attempt to detect any new hardware. Then it will give you the option to “select the hardware from a list." Choose the option to select from a list, then click the Next button. In the list select "modem" and click on the Next button. Then it will give you the option to let windows "try to detect your modem" or "select the modem from a list."



PnP will not be able to detect your modem if it's a model developed after your Windows installation disc was mastered. Nor will it appear on the list. Just select the closest match from the list, then update the driver


afterwards.



If Plug and Play installs old drivers, open the Control Panel "System" utility. Click on the Device Manager tab and in the device type list, open the branch for "Modem". Select the name of the modem and click on the "properties" button. The modems "Properties" dialog box will open. Select the "Driver" tab and click on the "Update Driver..." button. The "Update Driver Wizard" appears. Use the Wizard to install the new modem driver.



Don't be surprised if the "Update Driver Wizard" updates the driver by removing the modem and adding it again (with the new driver).



The modem "driver" will most likely not be a single file. It might be a group of files with extensions like .vxd, .exe, .ini, .dll, etc. The list of files is contained in a text file with the extension .inf. So when you install the "driver" you are actually reading the files and other configuration from the .inf file.



Step 4. Don't forget to reconfigure your dial-up connection with the new modem. If you are a system
administrator, don't forget to see that everyone else's dial-up connection gets updated as well.



Using the four steps described above, you can work around Plug and Play to properly install a modem with the latest drivers.




Permission is granted for the below article to forward, reprint, distribute, use for ezine, newsletter, website, offer as free bonus or part of a product for sale as long as no changes are made and the byline, copyright, and the resource box below is included.

System Restore: The Big Undo

System Restore is the ultimate band-aid fix for buggy Microsoft Windows. If you make a hardware or software change to your Windows Me or Windows XP system, and then it doesn't work right, System Restore acts like a giant "undo".

For System Restore to work, you need a "restore point" to go back to. A restore point saves a copy of the registry, drivers, and crucial operating system files. The files are saved as compressed .cab files in a folder named _RESTORE/ARCHIVE.


System Restore monitors all partitions on your computer (Windows XP lets you select which drives to monitor) and automatically creates restore points. The actual number of restore points saved depends on how much disk space has been allocated for System Restore. System Restore will not run if your system has less than 200 MB of free space.


= Types of Restore Points


- System Check Points: Scheduled restore points created by Windows. System Restore automatically creates a restore point every 10 hours (if your computer is on). Your computer must be idle for a few minutes before a restore point can be created.


- Manual Restore Points: Just before you make a hardware or software change to your system, you can maually create a restore point.


- Installation Restore Points: Restore points created by an installation program. Not all installation programs create a restore point.


= Make sure System Restore is enabled


1. Select Start | Settings | Control Panel and open System Utility.


2. On the Performance tab, click on the [File System] button. The "File System Properties" dialog box appears.


3. In the File System Properties" dialog box select the "Troubleshooting" tab.


4. On the "Troubleshooting" tab, make sure the "Disable System Restore" checkbox is not checked.


= To Create a Restore Point


1. Select Start | Programs | Accessories | System Tools | System Restore. The "Wecome to System Restore" window will appear.



2. In the "Welcome to System Restore" window, set the "Create Restore Point" radio button. Then click in the [Next] button. The "Create Restore Point" window will appear.


2. In the "Create Restore Point" window, enter a name for your restore point. For example, "Before Modem Upgrade". Then click on the [Next] button.


3. After a period of disk activity, the "Confirm New Restore Point" window will appear displaying the date and name of your restore point. Click on the [OK] button.


= Restoring Your System



You made a hardware or software change to your system, and now it doesn't work right. If Windows won't start, press the F8 key while your computer is starting. The "Startup Menu" should appear. In the Startup Menu select "Safe Mode". In safe mode, or if Windows does start, select


Start | Programs | Accessories | System Tools | System Restore


The "Welcome to System Restore" window will appear. Click on the [Next] button. On the "Choose a Restore Point" page, click on a restore point to highlight it. If there are no restore points listed, click on the [back arrow] button on the calendar until you find the most recent restore point. Then click on the [Next] button. System Restore restores your system to the state it was in at the restore point you selected
and then restarts your computer.


= Note: System Restore does not undo any changes that you made to files you created with your applications. If a restore doesn't work, you can undo it, and select a different restore point.


When Microsoft created this big band-aid fix called System Restore, they admitted that Windows is an unstable operating system. Now we should be able to get compensated for all the productivity we lost because of Windows crashing.

Learn How To Install A Sound Card Fast

Sound Card installation is indeed simple and rather straight forward,that is,when you know how to do it. Opening the system unit can be a scary task for some of us,especially if we have not performed this task before.


The key is to be calm,take your time,and make it fun. Look forward to looking inside the computer and see just how many components you can readily identify. PC Repair's cdrom one and the PC Test cdrom are filled with photos and video clips of these components. Remember to touch a doorknob or any grounded metal object to remove static electricity from your body.To install your new sound card,let's perform the following.



OPEN THE SYSTEM UNIT


Remove the system unit cover and locate an empty expansion bay.Note that the rear cover of the slot may have to be removed on most computers.Before touching anything,ground yourself to remove any buildup of elecrtical static charge from yourself. Touching the computer case or a boorknob will do the job.



With the cover removed from the system unit,lay the computer on its side.You may have to remove other connections or devices to have clear access to the empty card bay.



Take notes of any devices or connections that you make so that you can refer to them during installation of the new card.



New sound cards must be installed in the PCI slot. After removing the small rear cover,remove the new card from its protective wrap.This wrap is intended to keep the card away from electrical static charge.



INSTALLING THE SOUND CARD


Grasp the card and align it with the PCI slot. Slowly but firmly press the new card completely in the PCI slot.Check to be sure no part of the yellow


contacts can be seen when the card is pushed in. Secure the sound card to the system unit by using the screw that you removed when removing the rear cover.Use this screw to secure the card to the case. If you have on sound installed on the motherboard and you want to install another card,most systems will disable the motherboard integrated sound.If not, consult your computer manual to find the correct jumpers to disable the motherboard sound.



Now the cdrom audio cable must be connected. Insert one end of the audio cable for the cdrom or dvd drive into the CD-IN socket of the sound card. The other end is inserted into the audio-out socket of the cdrom or dvd drive.



Check and double check all connections before you replace the system unit cover.If all connections are good,replace the cover and reboot the system after all peripherals are reconnected.



REPLACE THE SYSTEM UNIT COVER


The computer should automatically detect the new card and attempt to install the device drivers needed to communicate with the card.Windows should prompt you to install the software needed to allow the card to communicate to the computer. The new card should have come with a cdrom with device drivers and other software for the card.Simply inserted the cdrom in the cdrom drive and select the cdrom installation when prompted.



Test the new sound card by re-booting the computer. You should hear the Windows startup sound if the card is operational.In some cases,the new card will be operational without rebooting your computer.



Installing or upgrading your sound card
is that easy.

Introduction to Dedicated Servers

A dedicated server is a single computer on a web-hosting network that is leased or rented, and dedicated to just one customer. A service provider monitors the computer’s hardware, network connectivity, and routing equipment, while the customer generally controls and maintains the server software. Dedicated servers are most often used by those who’ve outgrown typical hosting accounts and now require massive amounts of data space and bandwidth, those with mission critical web sites, web hosting companies, or those who have special needs. Dedicated servers are housed in data centers, where service providers can monitor them close-up and have hands-on access to them.

The primary advantage of using a dedicated server over a typical shared hosting account is the sheer amount of resources and control available to you, the customer. In many cases, the client is at liberty to install whatever software they desire, giving them greater flexibility and administrative options. Dedicated server clients do not share resources, as those with shared hosting plans do; but rather, are at liberty to use all the resources available to them.


Managed Servers vs. Unmanaged Servers


There are two types of dedicated servers available today: Managed Dedicated Servers and Unmanaged Dedicated Servers.


An Unmanaged Dedicated Server leaves nearly all the management duties of running a server in the purchaser’s control. The customer in this case, updates software on their own, applies necessary patches, performs kernel compiles and operating system restores, installs software, and monitors security. With this type of dedicated server, the consumer is solely responsible for day-to-day operations and maintenance. The service provider, in turn, monitors the network, repairs hardware problems, and troubleshoots connectivity issues. Additionally, some service providers offer partial management of services, such as network monitoring, software upgrades and other services, but leave the general upkeep of the server in the hands of the client. An unmanaged dedicated server is best for someone with server management experience.


A Managed Dedicated Server is generally more proactively monitored and maintained on the part of the service provider. When renting or leasing a managed server, the service provider or host carries out the responsibility of software updates and patches, putting security measures in place, performing hardware replacements, and also monitoring the network and its connection for trouble. In other words, when utilizing a managed dedicated server, the host provider will perform both hardware and software operations. A managed dedication server solution works well for the customer with limited server management experience or limited time in being able to perform the duties necessary to keep a server running and online.


Technical Aspects In Choosing A Server


When choosing a dedicated server, there are several things to consider: Operating System, Hardware options, Space and bandwidth.


The Operating System of a server is similar to that on your own personal computer; once installed, the operating system enables one to perform tasks more simply. There are a bevy of server operating systems available today including Linux-based and Windows-based software. The operating system you choose should be directly relational to what operations your server will be performing, which types of software you’ll need to install and also, what you’re more comfortable with.


Hardware Options are also something to consider when choosing a dedicated server. You’ll need to pick a
processor that’s up to the task, the amount of memory you wish installed, firewall options, and the size of the hard drive.


A certain amount of bandwidth is generally included when renting or leasing a dedicated server. Once you ascertained how much bandwidth you will require, you can adjust that limit with your service provider. The space you’ll be given is generally directly relational to the size of your hard drive. Some hosts also give clients the choice of uplink port speed (usually 10Mbps/100Mbps).

Protect Your PC from Viruses, Worms & Trojans

Each of the items in the checklist below is part of a broad and easy to implement security policy.

If you create a similar program, you can protect yourself and your PC from the numerous threats to your security and privacy.

1. Install all windows security patches for your operating system from the Microsoft Update site - it's free! All that's required to keep your operating system up to date is an Internet connection.

2. Install and configure a firewall - either a hardware or software based firewall is a must! If you are using a router, it probably has firewall capabilities included. Software firewalls are available at minimal cost; one of the best is free!

3. Install and configure antivirus software - the cost is minimal, there are even free versions available - the protection is priceless! Update it daily - scan your drives weekly - it can all be automated with most programs.

4. Create a backup - even the best plan can be circumvented - be prepared for the worst with a complete backup of your hard drive! If you already have a CD burner and software installed in your machine, you probably have

the tools to create a complete system backup - for only the cost of a few CD-R's!

Obviously, the costs to properly protect yourself from the worst threats to your security are almost nil. If you need help with any step above, simply use a Google search to find help - it's freely available.

Follow these four simple steps and you will have implemented comprehensive and complete protection for your PC. If you are unable to initiate your own plan, hire an expert to do the job. You won't be sorry!


-----------------
Mike Burstein has been helping the SOHO and Small Business community grow & prosper for over 20 years by solving start up problems, creating best practices, automating their offices, getting free publicity and dramatically increasing traffic and sales. http://www.sohowiz.com/

Caring for a Laptop

1. Handle the laptop with care. Try not to bump it or drop it.
2. The laptop can become damaged if you expose it to extreme temperatures. Never leave your laptop in the car for any extended period – the interior of a car can become extremely hot or cold.
3. Do not leave the laptop unattended in the car or a public place. Laptops are prime targets for theft! If you MUST leave the laptop in the car – leave it in the trunk where it is not clearly visible.
4. If the laptop has been left in the cold, let the laptop warm up to room temperature before turning it on.
5. If you need to clean the display, do so with a soft dry lint free cloth. Do not use any harsh detergents, Windex, alcohol or ammonia. Only use cleaning agents designed for laptop/lcd screens.
6. Move the laptop as little as possible while in actual use.
7. Do not pick up or carry the laptop by the display screen.
8. Never check the laptop in as luggage when traveling by airplane. Always take it with you as carry on luggage.
9. Do not eat or drink over the laptop – accidents can and DO happen.
10. If using a dialup modem – always unplug the modem from the wall when a storm is approaching. Lightening can travel through phone lines and render your laptop useless.

If you take a bit of care, you should never have to worry about returning the laptop in anything but pristine condition.

The Top 10 of Basic Computer Maintenance

1. Backup, backup backup! Backing up your data just means saving your files to a separate location (like a cd, floppy or zip disk) so in event of disaster you can easily copy your files back onto your computer. How often really depends on you. Just ask yourself, "If I only back up once every 3 months, would anything I saved on my hard drive since the last time I saved it on a backup be allright if I could NEVER get it back?"

2. Invest in an UPS (uninterruptible power source). A UPS is a wonderful device that works as a surge protector and a battery backup all in one! Not only does it keep your computer safe from electrical spikes that can be traveling through the lines, it also gives you time to save your work, and properly power down your computer in event of a power failure. You don't lose your work, and your computer gets to be shut down properly.

3. Never turn the computer off with the power switch. The one exception to this rule is when your computer locks up and your hard drive is not running (the hard drive light is not blinking). In this situation, you can turn the power off without harmful effects to the hard drive. As cutting the power can also result in lost data or Windows files, you should only do this when you have to.

Doing this can help prevent permanent hard drive damage caused by the hard drive heads contacting the surface of the drive disc. This can prevent a host of Windows problems.

Whenever possible, recover from crashes by pressing the Ctrl + Alt + Delete keys at the same time and going into your Task Manager. You can often find programs that are not responding in here, and chose to close them from this utility. Press Clt + Alt + Delete again to reboot your computer from this screen.

4. Scan disk and defrag once a month. These utilities help to keep your hard drive in optimal shape and error free.

5. Do not unplug peripheral devices while the power is turned on. Unplugging devices such as your mouse, keyboard, printer etc with the power on can short out the connector socket or even the motherboard itself.

The only time you would unplug something while the power is on, is if the device is hot swappable/pluggable. If you are unsure if something is hot swappable or not, power down first to play it safe.

6. Remove programs from your startup. Often when you install a program, it will ask you whether it should load up as soon as Windows loads (or just decide to do so on its own). The more programs you have trying to start up at the same time, the slower your computer will start. Also, all those programs running in the background while you try to work will slow your computer's response time.

In windows 98, ME, and XP, you can do this by going to your Start -> Run -> in the command box type in 'msconfig' and a small window will appear. Go to the tab marked "Startup" and you can chose what items to remove from there.

In Windows 2000, you can do this by going to your Control Panel -> Administrative Services -> Services.

7. Run virus checks and adware/spyware scans regularly (at least once a week). There are so many types and variations of viruses, spyware and adware floating around that at times it may seem daunting to even have internet access on your computer. However, regular scans with your virus scanner, and adware scanners, can ensure your computer remains healthy.

8. Keep disks handy. If the worst thing happens, and you need to format your system for one reason or another, then it is a good idea to have all your driver disks, operating system disks, backup disks and so forth in a readily available place. Running around in a panic at the 11th hour because you cannot remember where the drivers are for your network card, is not a good place to be.

9. Keep your software updated. Software developers are always writing and releasing patches that update the software you have already bought from them. A lot of these patches fix problems you may be experiencing yourself with a particular program.

Other patches plug security leaks. Still other patches update reference files for your virus/spy/adware scanners to make sure you are scanning for as many variants as possible. So make sure you regularly update/patch your operating system, virus scanners, and various other applications!

10. Develop a schedule of maintenance practices. All this advice is meaningless if you keep forgetting to do it, or only remember after something has gone wrong. Write yourself up a maintenance schedule, with a list of what tasks should be performed daily, weekly, and monthly.

If you develop a routine and stick to it, then you should avoid the larger problems by always being on top of the smaller ones!

Keeping Old Computers Alive

There are many reasons to replace your computers before they could reasonably be called old. Big corporations may replace their computers every three years or less. I usually recommend that nonprofits replace their computers every four years. One reason to do this is so computers are replaced before they fail, so that down-time can be scheduled instead of being caused by unexpected failure. Productivity increases with newer computers, as people spend less time waiting for programs to open and respond to commands.

Newer computers have newer technology, which means improved security, stability, and new features. Or maybe there is a new software package you want to use -- and your old computer doesn't meet the system requirements.

But there are good reasons to keep old computers around. Maybe you just don't have the money to buy a new one. Or you may be in a part of the world where replacement computers are not only expensive -- they're hard to come by. Or maybe you want to wait as long as possible before sending the lead, mercury, and other toxic materials in your computer into the environment, and using more resources to build a new computer that you may not yet need.

For any of these reasons, you might want to keep your old computer running well, even if it is four, five, or six years old.

(If you're interested in keeping older Macs running, read "Resources for Older Computers" on TechSoup.)

Extending the Usable Life of a Computer

As computers get older, different things can go wrong. You may experience problems with the software, the operating system may respond sluggishly, or you may receive error messages. Maybe you can't open a program, or it crashes unexpectedly. You may also run into hardware problems: the CD-ROM drive won't open, your floppy drive won't reliably read disks, or your modem just stops working.

To extend the life span of a computer, consider what can go wrong, how to prevent and recover from those problems, and how to change the way you use your computer:

1. What Can Go Wrong with Software?
2. Preventing Problems with Software
3. What Can Go Wrong with Hardware?
4. Preventing Mechanical Hardware Problems
5. Preventing Electrical Hardware Problems
6. Upgrading Hardware
7. Changing Hardware Roles
8. Changing Operating Systems
9. Changing Paradigms

What Can Go Wrong with Software?

Problem: Too Much Software
The biggest software problem on old computers is that there is too much of it. When a computer has been in an office for a long time, it tends to accumulate software like the junk drawer in your kitchen. Having too much software can cause a variety of problems.

Unnecessary software can take up too much room on the hard drive. If the hard drive is completely full or nearly full, the operating system won't run well. On a newer computer, having lots of software is less of a problem because new hard drives tend to be big. But on an old computer with a small hard drive, your system may respond sluggishly.

In addition, as programs are added to a computer, they may take up more of its memory. Some programs, particularly little ones downloaded from the Internet, stay active in your system's RAM even when you're not using them in order to open more quickly when you do want to use them. In Windows, these "memory resident" applications can often be seen in the system tray in the lower right-hand corner of the screen. In Mac OS 9, you might have extensions taking up memory that really aren't needed. On a newer computer with RAM to spare, lots of memory resident applications may not be a big deal. But on an old computer with little RAM, you should free up as much memory as possible.

Solution: Remove Unnecessary Software
First, decide what software is necessary. Consider the difference between "need" and "want." Be ruthless. You may want iTunes so you can listen to streaming audio while you work, but do you need it? Old computers can't afford such luxuries; only keep what you really need to do your work.

In Windows, go to the Add/Remove Programs control panel. Determine for certain which software applications you don't need. If you're not sure, make certain that you have the original installation disks so you can reinstall if necessary. Then uninstall the software you don't need.

If software you do need shows up in the system tray, you may be able to disable its tendency to always stay open. For example, in Microsoft Windows you may see the icon for MSN Messenger in your system tray. In the options for the program you can set it not to launch automatically when the computer starts up. This will free up some memory for other purposes.

In Mac OS 9, open the Extensions Manager and disable extensions you don't need. If you don't know what you need and what you don't, consult with an expert.

Problem: New Software, Old Hardware
It's a sad fact, but you can't install just any software on any computer. For example, let's say you have a Pentium II with 128 MB of RAM running Windows 2000. If you use the right software, you won't have problems with this set-up. But if you install the latest version of Photoshop, it just won't work. I frequently find older computers with installed with software that just won't work well -- such as Mac OS X on an original bondi blue iMac. Even if you can install it, that doesn't mean it will run well.

Solution: Stay Within Your Limits
Before installing any new software, check the system requirements. Make sure that it is not more than your computer can handle. Make sure you have enough room on the hard drive and that it is compatible with the operating system you're running. If the software needs more than you're able to provide in terms of system resources, don't install it.

But what if you need to add software to your older computer? For example, let's say you want to add Microsoft Access to a computer in order to open a database. When you go to TechSoup Stock, you find that your nonprofit is eligible to order a donated copy of Microsoft Office Professional, which includes Microsoft Access. But wait -- they only offer Office 2003, which has high system requirements. What to do? You could upgrade your hardware to meet the system requirements (more on that later), or you could pick an earlier version of the software -- say, Office XP.

"But Office XP isn't available through TechSoup Stock!" you wail. I'll let you in on a little secret. When you obtain a software license for Microsoft products through TechSoup Stock, that license entitles you to use older versions of the software. I know this is a little confusing; the point is, eligible organizations can obtain older versions of Microsoft products through TechSoup Stock. (Read more about the process on TechSoup Stock -- although the instructions refer to Windows XP, it works for other Microsoft software, too.) If you're not eligible to order donated software through TechSoup Stock, you may be able to order discounted software from an Open Charity License reseller -- this principle applies to these licenses, too. You can buy Office 2003 and install Office XP.

This act of buying new software but installing older software is sometimes called "downgrading." The rules vary from vendor to vendor, so do some research before assuming you can downgrade.

Problem: Spyware
This is mostly a problem with Windows. Spyware, adware, and other junk software on your computer is always undesirable, regardless of the age of your computer. But again, on an old computer every bit of memory is precious. You cannot allow these invasive programs to steal your valuable system resources.

Solution: Spyware Removal Tool
Use a spyware removal tool such as Spybot Search and Destroy or Ad Aware. A nice feature of Spybot is that it can "innoculate" your computer against future infections. Best of all, it's free. Read more about removing malware on TechSoup.

Problem: Viruses
As with spyware, this problem mostly affects Windows users. (There just aren't that many viruses for the Mac OS.) Viruses are a problem with computers new and old, but they are more likely to turn up on old computers. This is simply because an old computer has been around longer, so it has a greater chance of being infected with a virus. There's also a greater chance users have lapsed on upgrading anti-virus software.

Solution: Anti-Virus Software
If you're going to run an old computer, you have to keep it clean if you expect it to perform. That means having up-to-date anti-virus software.

Preventing Problems with Software

Performing regular maintenance will forestall problems with your operating system and other software. That means installing updates from the software vendor, defragmenting the hard drive, running Scandisk on Windows 98 or chkdsk on Windows 2000 or Windows XP. Be prudent about installing only what you need to do your work. Don't install software just for fun. Ultimately, you'll be a lot happier if your computer is running well.

What Can Go Wrong with Hardware?

There's basically only one thing that goes wrong with hardware: it breaks. If it's not broken, the problem isn't with the hardware. By "broken," I mean worn out, bent, burned up, cracked, smashed, or otherwise inoperable.

So what can break? Just about anything in your computer can break, but the parts that move are more likely to break:

• ventilation fans
  
• the fan in the power supply
  
• the fan on the processor
  
• the hard drive
  
• the CD-ROM drive
  
• the floppy drive
  
• moving parts in the printer
  
• moving parts on the mouse

If something appears to be broken, first determine whether it's actually broken. I won't go into detail here on troubleshooting hardware, but suffice to say that cracking open the mouse and cleaning the dust bunnies out of the rollers can make a "broken" mouse work like new.

Preventing Mechanical Hardware Problems

You can help keep moving parts running by using them gently and removing sources of friction. The biggest source of friction is dust, including hair and cigarette ashes.

Keeping your work area clean will prolong the life of your computer. Dust your desk regularly. Vaccuum the floor to reduce the amount of dirt there. Don't smoke in your office: you already know it's not good for you or your coworkers, and now you know it's not good for your computer. Once a year or so, open your computer's case and blow out any dust with a can of compressed air.

Preventing Electrical Hardware Problems

Power surges can break electronics. Test your electrical outlets to see if they are properly grounded, and use a good-quality surge protector to protect your equipment from voltage spikes. Dusting out computers also helps lower their temperature, which improves performance and prolongs the life of electrical components.

Upgrading Hardware

• RAM: To see the biggest increase in performance, increase the amount of RAM in an older computer. Put in as much as the computer will support. You can find what kind of RAM you need and how much your computer will support by looking at the documentation for the computer on the manufacturer's Web site. If you have a generic computer or can't find the information, consult with a expert to figure out what you need and where you can find it. Don't assume that just because it fits you can drop a 256MB RAM DIMM in your computer. Make sure that the computer supports the size and the type of the RAM you are installing.
  
• Video card: Replacing the video card with a newer one that has more memory can also improve performance. If your older computer has an AGP slot, replacing a PCI or onboard video adapter with an AGP video card can speed up the computer.
  
• Hard drive: An old hard drive is probably a slow hard drive. Replacing the hard drive in your old computer with a new one will give your machine an added boost. In an older machine with a slow (66 MHz) IDE controller, you should consider adding a PCI IDE 133 expansion card to match a new IDE 133 hard drive. Keep in mind that replacing the hard drive probably means reinstalling the operating system and all your programs, so don't plan on taking this step unless your time (or the environment) is more important to you than your money.
  
• Processor: It's usually more trouble than it's worth to replace the processor or the motherboard.

If you're upgrading on a budget, you may be able to get used parts for free or for cheap from a computer recycling organization.
Changing Hardware Roles

If a computer is too old to be servicable as a desktop computer for one purpose, you may yet find a use for it.

• Appropriate assignment: Does your receptionist need to do work with graphics or PowerPoint? Give him your newest computer. Does your intern really only answer e-mail and surf the Web on the computer? An older computer might fit the bill. When a computer is suited to the task at hand, its age doesn't matter as much.
  
• File or print server: An older computer can often make a perfectly adequate file or print server. Windows 98 also doesn't have the same 10-user limit that Windows 2000 imposes.
  
• Firewall or router: You could also put an old computer into service as a firewall or router using Coyote Linux. All you need is any old computer with a working motherboard, two network cards, and a floppy drive. No CD-ROM or hard drive are required.

Changing Operating Systems

One of the best ways to bring new life to an old PC is to erase it and start over with some version of Linux. Some Linux distributions such as Cobind are specifically intended for use on older hardware. Cobind Linux has many features of a modern operating system. Like all versions of Linux, it is unbelievably stable and highly secure. Cobind will run well on a Pentium II 300MHz processor with 64MB of RAM and a 2GB hard drive.

Changing Paradigms

Old computers can make excellent terminals in a thin-client network. In your standard small office environment, programs are run on separate computers: I might run an e-mail program on my computer, while you run a database on your computer. In a thin-client network, all programs are run on one computer, which is connected to many terminals so that multiple users can access that one computer system at once. So instead of replacing old computers with new ones, an organization could use a single higher powered machine as a terminal server, and use the old PCs as terminals. A terminal in a set-up like this doesn't need a hard drive, much of a processor, or memory. It doesn't do any processing at all -- it just provides a window onto the terminal server.

Depending on the applications that staff need to run, an organization could use the same old Pentium II PCs for years. The only reason to finally remove them from service would be hardware failure.

Basic Computer Maintenance

Basic Computer Maintenance

Keeping Software Up-to-date on Public Access Computers

These tips have been adopted from Aaron Schmidt’s “Smart Computing at Your Library” presentation at the Internet Librarian 2005 conference in Monterey, California on October 24. You can view Aaron’s original presentation at his web site.

These tips apply to public access computers (PAC) running any version of the Microsoft Windows operating system. The goal of these tips is to help you keep those PACs up-to-date with the latest critical software releases.

You should also note that any public access or shared computer security system, such as Centurion Guard, Deep Freeze, Fortres 101, or the Microsoft Shared Computer Toolkit, will probably need to be disabled or bypassed to perform these updates. How this will need to be done will depend on the particular security system. It could mean logging in as an administrator, unlocking via a password, or even using a physical key.

In some cases these tips recommend alternative software packages that differ from the default applications found on most Windows PACs. The following substitutions are specifically recommended:

· Use Mozilla Firefox as the default web browser in place of Internet Explorer.

· Replace the default version of RealPlayer with the spyware-free “BBC version.”

· Replace the Microsoft Virtual Machine (VM) with the Java Runtime Environment (JRE).

Beyond the obvious implications for computer security, keeping software applications up-to-date can prevent annoying update messages appearing while patrons are using the PACs. In most cases, patrons will not have the correct operating system permissions to take action on prompted updates, so if library staff take the time to perform these update tasks periodically, it will help to ensure “smooth sailing” for your PAC users.

Many of the resources in the last column of the table below lead to web pages from which you can download updated software versions. It’s a good idea to check what version of a particular product you are currently using before visiting the relevant download page – if you already have the latest version installed, there’s no need to download a new version. You can determine the version of any installed program by opening the program, and going to the Help / About (product name) menu option.

In general, it is recommended that you have library staff perform these tasks outside regular business hours, when the PACs are not in use by patrons. Performing these tasks regularly on a weekly, bi-weekly or monthly basis will keep help keep your PACs fully functional and (hopefully) trouble-free.

Multiple Programs

You can run two programs on the same line in Windows XP's Command Prompt window. To run two programs, you type in their names separated by an ampersand (&). For example, you'd type:

Program1 & Program2

and press Enter. In this example, Program2 starts as soon as Program1 finishes executing.

Put It on the Desktop

You can get to Windows Explorer much more easily if you put it on the desktop.

To place a shortcut to Windows Explorer on your desktop, run Windows Explorer and navigate to \Windows. Locate Explorer.exe and use the right mouse button to drag its icon to the desktop. When you release the mouse button, choose Create Shortcut(s) Here. Now you just double-click your new shortcut to open Windows Explorer.

Make it Wide Always

If you'd like to have your directory listings show up in wide format, try this. You need to change the DIRCMD. Click Start, Settings, Control Panel, and double-click the System icon. When the System Properties dialog box opens, click the Advanced tab. Next click the Environment Variables button. Then click the New button in the User Variables area. In the Vairable Name field, type

dircmd and press Tab to move to the Value entry box. In Value, type /w and click OK. Finally, click OK to close the dialog box and apply your new settings. From this point on, typing DIR at the Command Prompt produces the wide listing.

Custom Internet Shortcuts

You can create your own custom shortcuts to Internet sites using Notepad. Just run Notepad and enter the following as shown here.

[InternetShortcut]

URL=http://www.yoursite.com

Choose File--Save As and then click the arrow at the right side of the "Save as Type" list box and select All Files.Name your file Yoursite.url and select a folder for it. Click Save to save the file. Note that you can name a file whatever you wish, but you must use the URL extension.

Block Pop-up with Internet Explorer

Block Pop-up Windows with Internet Explorer

Many legitimate advertisers on the Internet use windows that pop up in the middle of your screen to display a message. They might also open when you click a link or button on a Web site, and they might open either over or under the window you wish to view. Some pop-ups are helpful. For example, if you click an image to see a larger version, it might open in a pop-up window. Unfortunately, some pop-up windows can contain inappropriate content or can be a way for you to accidentally download dangerous software (called spyware or adware) onto your computer.

With Windows XP Service Pack 2 (SP2) Internet Explorer allows you to prevent most pop-up windows from appearing over pages you want to view while you're using the Internet.

Using Pop-up Blocker

When you install SP2, Pop-up Blocker is turned on in Internet Explorer and set to the medium setting, which means it will block most automatic pop-ups. The default settings for the pop-up blocker allow you to see pop-ups that are opened when you click a link or button on a Web site. Pop-up Blocker will also play a sound and show the Information Bar when a pop-up is blocked. You can adjust these settings so that Pop-up Blocker works the way you want it to.

To change Pop-up Blocker settings

1.	Open Internet Explorer.
2.	On the Tools menu, point to Pop-up Blocker, and then click Pop-up Blocker Settings.

If you want to see pop-up windows from a specific Web site, type the address (or URL) of the site in the Address of Web site to allow box, and then click Add.

Tip To temporarily allow a site to display pop-ups, click the Information Bar when it notifies you that a pop-up has been blocked. Then click Temporarily Allow Pop-ups.

To block pop-ups even if they are launched when you click a link or button on a Web site

1.	Open Internet Explorer.
2.	On the Tools menu, point to Pop-up Blocker, and then click Pop-up Blocker Settings.
3.	Select the High setting in the box near the bottom of the dialog box.

Note If you want to see pop-ups that are blocked when you have this setting turned on, hold down the CTRL key while the window opens.

Troubleshooting Pop-Up Blocker

If you've installed SP2 and you still see pop-ups in Internet Explorer, try the possible solutions below.

•	Make sure Pop-up Blocker is turned on: Pop-up Blocker is turned on by default, but someone may have turned it off.

To turn on Pop-up Blocker

1.	On the Tools menu, point to Pop-up Blocker.
2.	Click Turn on Pop-up Blocker.

•

Rid your system of spyware: If you get similar pop-up windows no matter what sites you visit or even if you're not on the Web at all, you could have spyware, adware, or other software on your computer that's launching pop-ups. To stop these pop-ups, you will have to identify the software, then remove it or change its settings to stop it from launching pop-ups. To learn more about this read How to Protect Your Computer from Spyware and Adware.

•

Some windows are not blocked: Pop-up Blocker is smart enough to not block pop-up windows that you open deliberately by clicking a link—for example, if you were on a travel reservation site and you clicked a link to open a pop-up window containing your confirmation details, this pop-up window would not be blocked because you opened it intentionally. Also, Pop-up Blocker will not block some pop-ups with certain types of animated content or pop-ups from Web sites that are in two Web content zones: Local intranet or Trusted sites. To learn more about security zones, see Working with Internet Explorer 6 Security Settings.

 

Introduction to TCP/IP

Summary: TCP and IP were developed by a Department of Defense (DOD) research project to connect a number different networks designed by different vendors into a network of networks (the "Internet"). It was initially successful because it delivered a few basic services that everyone needs (file transfer, electronic mail, remote logon) across a very large number of client and server systems. Several computers in a small department can use TCP/IP (along with other protocols) on a single LAN. The IP component provides routing from the department to the enterprise network, then to regional networks, and finally to the global Internet. On the battlefield a communications network will sustain damage, so the DOD designed TCP/IP to be robust and automatically recover from any node or phone line failure. This design allows the construction of very large networks with less central management. However, because of the automatic recovery, network problems can go undiagnosed and uncorrected for long periods of time.

As with all other communications protocol, TCP/IP is composed of layers:

• IP - is responsible for moving packet of data from node to node. IP forwards each packet based on a four byte destination address (the IP number). The Internet authorities assign ranges of numbers to different organizations. The organizations assign groups of their numbers to departments. IP operates on gateway machines that move data from department to organization to region and then around the world.


• TCP - is responsible for verifying the correct delivery of data from client to server. Data can be lost in the intermediate network. TCP adds support to detect errors or lost data and to trigger retransmission until the data is correctly and completely received.


• Sockets - is a name given to the package of subroutines that provide access to TCP/IP on most systems.

Network of Lowest Bidders

The Army puts out a bid on a computer and DEC wins the bid. The Air Force puts out a bid and IBM wins. The Navy bid is won by Unisys. Then the President decides to invade Grenada and the armed forces discover that their computers cannot talk to each other. The DOD must build a "network" out of systems each of which, by law, was delivered by the lowest bidder on a single contract.

The Internet Protocol was developed to create a Network of Networks (the "Internet"). Individual machines are first connected to a LAN (Ethernet or Token Ring). TCP/IP shares the LAN with other uses (a Novell file server, Windows for Workgroups peer systems). One device provides the TCP/IP connection between the LAN and the rest of the world.

To insure that all types of systems from all vendors can communicate, TCP/IP is absolutely standardized on the LAN. However, larger networks based on long distances and phone lines are more volatile. In the US, many large corporations would wish to reuse large internal networks based on IBM's SNA. In Europe, the national phone companies traditionally standardize on X.25. However, the sudden explosion of high speed microprocessors, fiber optics, and digital phone systems has created a burst of new options: ISDN, frame relay, FDDI, Asynchronous Transfer Mode (ATM). New technologies arise and become obsolete within a few years. With cable TV and phone companies competing to build the National Information Superhighway, no single standard can govern citywide, nationwide, or worldwide communications.

The original design of TCP/IP as a Network of Networks fits nicely within the current technological uncertainty. TCP/IP data can be sent across a LAN, or it can be carried within an internal corporate SNA network, or it can piggyback on the cable TV service. Furthermore, machines connected to any of these networks can communicate to any other network through gateways supplied by the network vendor.

Addresses

Each technology has its own convention for transmitting messages between two machines within the same network. On a LAN, messages are sent between machines by supplying the six byte unique identifier (the "MAC" address). In an SNA network, every machine has Logical Units with their own network address. DECNET, Appletalk, and Novell IPX all have a scheme for assigning numbers to each local network and to each workstation attached to the network.

On top of these local or vendor specific network addresses, TCP/IP assigns a unique number to every workstation in the world. This "IP number" is a four byte value that, by convention, is expressed by converting each byte into a decimal number (0 to 255) and separating the bytes with a period. For example, the PC Lube and Tune server is 130.132.59.234.

An organization begins by sending electronic mail to Hostmaster@INTERNIC.NET requesting assignment of a network number. It is still possible for almost anyone to get assignment of a number for a small "Class C" network in which the first three bytes identify the network and the last byte identifies the individual computer. The author followed this procedure and was assigned the numbers 192.35.91.* for a network of computers at his house. Larger organizations can get a "Class B" network where the first two bytes identify the network and the last two bytes identify each of up to 64 thousand individual workstations. Yale's Class B network is 130.132, so all computers with IP address 130.132.*.* are connected through Yale.

The organization then connects to the Internet through one of a dozen regional or specialized network suppliers. The network vendor is given the subscriber network number and adds it to the routing configuration in its own machines and those of the other major network suppliers.

There is no mathematical formula that translates the numbers 192.35.91 or 130.132 into "Yale University" or "New Haven, CT." The machines that manage large regional networks or the central Internet routers managed by the National Science Foundation can only locate these networks by looking each network number up in a table. There are potentially thousands of Class B networks, and millions of Class C networks, but computer memory costs are low, so the tables are reasonable. Customers that connect to the Internet, even customers as large as IBM, do not need to maintain any information on other networks. They send all external data to the regional carrier to which they subscribe, and the regional carrier maintains the tables and does the appropriate routing.

New Haven is in a border state, split 50-50 between the Yankees and the Red Sox. In this spirit, Yale recently switched its connection from the Middle Atlantic regional network to the New England carrier. When the switch occurred, tables in the other regional areas and in the national spine had to be updated, so that traffic for 130.132 was routed through Boston instead of New Jersey. The large network carriers handle the paperwork and can perform such a switch given sufficient notice. During a conversion period, the university was connected to both networks so that messages could arrive through either path.

Subnets

Although the individual subscribers do not need to tabulate network numbers or provide explicit routing, it is convenient for most Class B networks to be internally managed as a much smaller and simpler version of the larger network organizations. It is common to subdivide the two bytes available for internal assignment into a one byte department number and a one byte workstation ID.

The enterprise network is built using commercially available TCP/IP router boxes. Each router has small tables with 255 entries to translate the one byte department number into selection of a destination Ethernet connected to one of the routers. Messages to the PC Lube and Tune server (130.132.59.234) are sent through the national and New England regional networks based on the 130.132 part of the number. Arriving at Yale, the 59 department ID selects an Ethernet connector in the C& IS building. The 234 selects a particular workstation on that LAN. The Yale network must be updated as new Ethernets and departments are added, but it is not effected by changes outside the university or the movement of machines within the department.

A Uncertain Path

Every time a message arrives at an IP router, it makes an individual decision about where to send it next. There is concept of a session with a preselected path for all traffic. Consider a company with facilities in New York, Los Angeles, Chicago and Atlanta. It could build a network from four phone lines forming a loop (NY to Chicago to LA to Atlanta to NY). A message arriving at the NY router could go to LA via either Chicago or Atlanta. The reply could come back the other way.

How does the router make a decision between routes? There is no correct answer. Traffic could be routed by the "clockwise" algorithm (go NY to Atlanta, LA to Chicago). The routers could alternate, sending one message to Atlanta and the next to Chicago. More sophisticated routing measures traffic patterns and sends data through the least busy link.

If one phone line in this network breaks down, traffic can still reach its destination through a roundabout path. After losing the NY to Chicago line, data can be sent NY to Atlanta to LA to Chicago. This provides continued service though with degraded performance. This kind of recovery is the primary design feature of IP. The loss of the line is immediately detected by the routers in NY and Chicago, but somehow this information must be sent to the other nodes. Otherwise, LA could continue to send NY messages through Chicago, where they arrive at a "dead end." Each network adopts some Router Protocol which periodically updates the routing tables throughout the network with information about changes in route status.

If the size of the network grows, then the complexity of the routing updates will increase as will the cost of transmitting them. Building a single network that covers the entire US would be unreasonably complicated. Fortunately, the Internet is designed as a Network of Networks. This means that loops and redundancy are built into each regional carrier. The regional network handles its own problems and reroutes messages internally. Its Router Protocol updates the tables in its own routers, but no routing updates need to propagate from a regional carrier to the NSF spine or to the other regions (unless, of course, a subscriber switches permanently from one region to another).

Undiagnosed Problems

IBM designs its SNA networks to be centrally managed. If any error occurs, it is reported to the network authorities. By design, any error is a problem that should be corrected or repaired. IP networks, however, were designed to be robust. In battlefield conditions, the loss of a node or line is a normal circumstance. Casualties can be sorted out later on, but the network must stay up. So IP networks are robust. They automatically (and silently) reconfigure themselves when something goes wrong. If there is enough redundancy built into the system, then communication is maintained.

In 1975 when SNA was designed, such redundancy would be prohibitively expensive, or it might have been argued that only the Defense Department could afford it. Today, however, simple routers cost no more than a PC. However, the TCP/IP design that, "Errors are normal and can be largely ignored," produces problems of its own.

Data traffic is frequently organized around "hubs," much like airline traffic. One could imagine an IP router in Atlanta routing messages for smaller cities throughout the Southeast. The problem is that data arrives without a reservation. Airline companies experience the problem around major events, like the Super Bowl. Just before the game, everyone wants to fly into the city. After the game, everyone wants to fly out. Imbalance occurs on the network when something new gets advertised. Adam Curry announced the server at "mtv.com" and his regional carrier was swamped with traffic the next day. The problem is that messages come in from the entire world over high speed lines, but they go out to mtv.com over what was then a slow speed phone line.

Occasionally a snow storm cancels flights and airports fill up with stranded passengers. Many go off to hotels in town. When data arrives at a congested router, there is no place to send the overflow. Excess packets are simply discarded. It becomes the responsibility of the sender to retry the data a few seconds later and to persist until it finally gets through. This recovery is provided by the TCP component of the Internet protocol.

TCP was designed to recover from node or line failures where the network propagates routing table changes to all router nodes. Since the update takes some time, TCP is slow to initiate recovery. The TCP algorithms are not tuned to optimally handle packet loss due to traffic congestion. Instead, the traditional Internet response to traffic problems has been to increase the speed of lines and equipment in order to say ahead of growth in demand.

TCP treats the data as a stream of bytes. It logically assigns a sequence number to each byte. The TCP packet has a header that says, in effect, "This packet starts with byte 379642 and contains 200 bytes of data." The receiver can detect missing or incorrectly sequenced packets. TCP acknowledges data that has been received and retransmits data that has been lost. The TCP design means that error recovery is done end-to-end between the Client and Server machine. There is no formal standard for tracking problems in the middle of the network, though each network has adopted some ad hoc tools.

Need to Know

There are three levels of TCP/IP knowledge. Those who administer a regional or national network must design a system of long distance phone lines, dedicated routing devices, and very large configuration files. They must know the IP numbers and physical locations of thousands of subscriber networks. They must also have a formal network monitor strategy to detect problems and respond quickly.

Each large company or university that subscribes to the Internet must have an intermediate level of network organization and expertise. A half dozen routers might be configured to connect several dozen departmental LANs in several buildings. All traffic outside the organization would typically be routed to a single connection to a regional network provider.

However, the end user can install TCP/IP on a personal computer without any knowledge of either the corporate or regional network. Three pieces of information are required:

1. The IP address assigned to this personal computer


2. The part of the IP address (the subnet mask) that distinguishes other machines on the same LAN (messages can be sent to them directly) from machines in other departments or elsewhere in the world (which are sent to a router machine)


3. The IP address of the router machine that connects this LAN to the rest of the world.

In the case of the PCLT server, the IP address is 130.132.59.234. Since the first three bytes designate this department, a "subnet mask" is defined as 255.255.255.0 (255 is the largest byte value and represents the number with all bits turned on). It is a Yale convention (which we recommend to everyone) that the router for each department have station number 1 within the department network. Thus the PCLT router is 130.132.59.1. Thus the PCLT server is configured with the values:

• My IP address: 130.132.59.234


• Subnet mask: 255.255.255.0


• Default router: 130.132.59.1

The subnet mask tells the server that any other machine with an IP address beginning 130.132.59.* is on the same department LAN, so messages are sent to it directly. Any IP address beginning with a different value is accessed indirectly by sending the message through the router at 130.132.59.1 (which is on the departmental LAN).