Dust can make the chips inside your computer run hotter and also clog cooling vents.

At least once a year, unplug your computer, open the case, and blow out the dust. Do not wipe it with a rag; use either your breath or an aerosol can of compressed air.

Your mouse and keyboard will also require occasional cleaning. You can pop off the key caps on your keyboard to get at dirt and hair between the keys.

You can also remove your mouse ball to clean it and the rollers inside the mouse.

Use a commercial spray cleanser applied to a cotton swab to clean your keyboard and mouse.

Software drivers let your applications talk to important peripherals. It’s a good idea to check with your computer’s manufacturer at least four times a year for the latest updates. The easiest way to do this is to access the manufacturer’s Web site; most companies normally make updated drivers available for download. If you don’t have Web access, call the vendor’s tech-support number.

You should keep your Windows based computer up-to-date via the Windows Update Service on the web.

Once you’ve installed a program on a Windows system, don’t rename the program’s directories or move its files from one place to another on your hard disk. If you do, your computer will likely lose track of key files. You can put your data files — the ones you create with the application — almost anywhere (although see Step 5). If you must change the location of an application or any of its subsidiary files, you should first uninstall the application and then reinstall it.

Never try to manually delete an application on a Windows system. Most applications make additions to system files when you install them, so it’s best if the application has its own uninstall program. If an application doesn’t come with an uninstall option, try the Windows 95/98/Me/XP /Vista Add/Remove Programs Control Panel. If the application doesn’t support the Windows 95/98/Me/XP/Vista  uninstall function, use a commercial utility such as PC Tools Registry Mechanic V8 or the most current version available.  

As the Windows uninstall utility is not always reliable about removing all the pieces of an application, you may want to use one of the commercial utilities in all cases. They do a better job.

A computer virus is a program that can make copies of itself. Most computer viruses do nothing more than this and are more of an annoyance than a danger. Some computer viruses, though, may also harm data and programs stored on a computer.

What types of viruses are there?

• Program viruses infect computer programs and become active when the infected program is run. 
• Boot sector viruses infect diskettes and hard disks and become active when an infected disk is used to start the computer. (On a Macintosh, merely inserting an infected disk can activate a virus.) 
• Macro viruses infect documents (files) through the macro programming capabilities of some newer programs. Macro viruses become active when an infected document is opened, and the program opening the document has its macro capabilities turned on (enabled).What is not a virus?

Trojan horse programs are designed to do something (usually something malicious) other than their supposed purpose. Trojan horse programs are sometimes classified with viruses. However, because they don’t make copies of themselves, they are not true viruses.

Some programs are designed as a joke, or prank, but are not viruses. For instance, warnings of a virus incorporated in a mail message with the phrase “Good Times,” “Join the Crew,” or “Penpal Greetings” in the header have, at times, been rampant. The only thing that spreads, however, with these “viruses,” is the messages warning people to look out for the supposed virus in their e-mail. And, it’s the person sending the message, not the computer, that causes the message to be copied and spread.

If you do not have an anti-virus utility on your computer, you should get one here Norton Antivirus 2009

How often you back up depends on how valuable your time is. If you’re working on an important file, save it to a floppy as well as to your hard disk. If you’re running a home-based business, you should invest in a tape backup drive and back up on a daily basis.

Most families can get by with a less rigorous backup schedule. Back up the files in your data folders (see Step 4) once a week, and perform a complete system backup every six months. You can back up your data files simply by dragging their folders to the icon for your floppy disk, CD or DVD.

If you’re a Windows 95/98/ME/2000/XP/Vista user, you can use the Backup program in Programs/Accessories/System tools. This lets you check off the folders you want to back up.

High-capacity removable disks, such as those DVD’s, are great for backing up a hard disk, and they can help keep down the clutter on your disk. A tape drive that can store from 400MB to 2GB of data is even better for backup, as it will keep media-swapping to a minimum. All tape drives also come with their own backup software.

First, it makes it easier to do “housecleaning” — deleting files you no longer need.

Second, keeping data files in their own well-labeled folders reduces the risk that you will inadvertently delete an important program or data file.

Finally, a well-organized hard drive is easier and faster to back up.

Create folders for each program and place only the appropriate data files in them.

Alternately, create folders for each member of the family. Give files and folders names that will make sense even after you’ve forgotten why you created them.

In addition to organizing your files, at least every two months you should delete files you no longer need. A disk filled to within 5 percent of capacity is more prone to errors — and a lot slower — than one that is not so chock-full.

Every day, you create new files, delete unwanted ones, and write updated versions of current files to your computer’s hard disk. Because of the way Windows and the Mac OS assign disk space to files, your hard disk can become fragmented over time (i.e., your files get placed in pieces all over the hard disk, because there is no contiguous space large enough to hold them). A fragmented hard disk slows disk access and makes it harder to recover from disk errors.

To DEFRAGEMENT a Windows 95/98/ME/XP/Vista hard disk, use the Disk Defragmenter program in Programs/Accessories/System Tools. On a Mac, use a utility such as the Speed Disk tool that comes with Norton Utilities for the Macintosh. You should defrag your hard disk every six months. You should also defrag it after you have created or deleted a lot of files in a short span of time.

Occasionally, a storage area called a sector on your hard disk goes bad. A utility called a disk scanner detects such “hard” errors and keeps a table of such sectors so that your operating system doesn’t try to use them to store files. In addition, a disk scanner detects “soft” errors, where the operating system has lost track of pieces of one or more files. ScanDisk (found in Programs/Accessories/System tools) is Windows 95/98/ME/XP built-in disk scanner, and it detects both hard and soft errors.

On the Mac, you can use the Disk First Aid program that comes with your system or the more powerful Disk Doctor utility included in the ubiquitous Norton Utilities for Macintosh. You should run a hard disk scan at least every month. In addition, if your computer crashes or you accidentally shut down without going through the proper shutdown procedure, run a disk scan as soon as you reboot.

If you are using Win95/98/ME , you need to make an emergency boot disk, which you can make with the Add/Remove Programs control panel. Select the Startup Disk tab, and you’re led through the process.

On Windows XP , you can generally boot directly from the Windows XP CD-ROM, however in some cases you may still need a set of boot floppies. In this case, click one of the links below to download a program to create boot floppies for Windows XP Home or Windows XP Pro editions.

Windows XP Home Boot Floppy Creator

Windows XP Pro Boot Floppy Creator

On Windows Vista a boot disk (sometimes called a startup disk) was a floppy disk or a compact disc (CD) that contained Windows startup files. If those same files on your hard disk were damaged, you could use the boot disk to get Windows started.

In this version of Windows, the Windows installation disc contains the files necessary to start Windows, so you can use it as a boot disk.

The installation disc includes Startup Repair and other tools on the System Recovery Options menu that you can use to attempt repairs or restore data from a backup.

Macintosh systems come with either a bootable CD-ROM or a bootable floppy disk, as does Norton Utilities for Macintosh — a must for all Mac owners.

The first preventive step you need to perform is to take an inventory of your computer system. This information will be vital if you later have to contact technical support or have your system serviced.

Start by noting your serial number and model number. With this information, your system manufacturer can determine the components of your system. If you’ve added components to your system, note the model and version numbers of the components. You’ll find this information in the documentation that accompanies add-on hardware.

Beyond these basics, you need to get details of your system’s configuration. On Windows PCs, this means copying and printing a few important system files that will come in handy if you later have a problem or need to speak to a tech-support person.

The simplest way to preserve your system configuration files is to run the Sysedit program.

With Windows 95/98/ME, click on Start, RUN, type SYSEDIT in the blank window, and click OK. It will bring up all your system files — from AUTOEXEC.BAT to SYSTEM.INI — in Wordpad windows.  From there, you can save them to a floppy disk and print them out.

With Windows XP/2000 and Vista, you can go into Accessories, System Tools, System Information to find and print  this important data. You may also want to copy and paste each section into Wordpad and save it with the name of the window.