Assuming your computer is running under Windows 98, 98SE, ME, 2000, or XP, then you may find these tips useful. These suggestions also assume that you're comfortable doing things in your computer other than opening a document, sending an email message or surfing the Web. If not, find someone who is (I can refer you to good technicians and I can also coach you so you can do it yourself).
Backup. There are many ways to back up files. If you have a lot of data an external hard drive is one way. I back up my computer by moving files to other computers in my office. You will probably want to compress the files to fit onto your backup media (CD, DVD or external hard drive). Microsoft's built-in backup program works great for this task. Go to My Computer, right-click on your hard drive (probably "C:,") choose Properties, then Tools; there you will see a button for doing a backup. Just click the button and complete the wizard.
It is also important to back up your e-mail each day. Outlook users have it easy; do a search on *.pst to find your Outlook data file. Then you can drag-and-drop the file to your backup media.
Some programs store stuff in places other than the My Documents folder, so if you chose that limited option for backups using the process above, then exploring the Application Data folder would be a good idea. If you do not know where it is, just do a search for it. The Application Data folder contains many sub-folders where programs might store data and personalized settings. If you do not back up the entire hard disk, you should use the drag-and-drop technique to back up the Application Data folder, too.
Don't turn your computer off. If you'll be back on your computer within 12 hours you should keep it running. The most demanding thing your computer does is to power up. It will work better longer if you are not constantly turning it on and off. Instead, go to your Control Panel and choose Display, then Power. Change the setting for hard disks to power down after an hour, or two, of inactivity.
Get rid of the surge suppressor. No sane person would use a power strip for their computer equipment, but if you know someone who does this goes for them, too. This may cost you a few bucks. Get yourself an Uninterruptible Power Supply (UPS). A decent one will cost around $65, but it may be the best money you can spend to protect your hardware. It will not wear out for many years, so it will last through a few generations of new computers. When the power fails the UPS will give you about 10 minutes or more to save your work and power everything down. Some come with software that will do the shut down automatically if you are not there.
When you turn your computer on, power up the monitor and any accessories first, and then power on the PC itself. When you turn the computer off reverse this process--first power down the PC, then the monitor and accessories. Doing this will protect your computer from some types of power spikes that circumvent the UPS.
Update your anti-virus software. Many anti-virus applications do this automatically, but if yours doesn't, make sure you do it manually. Even if your software updates automatically, it is a good idea to verify that it's working properly. For many of these applications you can right-click on the software's SysTray icon (look down in the right corner near the clock) and choose "Update" or "About" or "Properties." One will probably tell you when your virus definitions were last updated.
Clean out spyware. Spyware happens. Clean it up. There are good free anti-spyware applications like AdAware from Lavasoft and Spybot Search and Destroy. I invested in Spyware Nuker. If you do not protect your system from spyware, it will eventually slow to a crawl. And privacy is a good thing--the spyware is designed to watch your online activities and sell you stuff.
Vacuum your PC and keyboard. If your intake fan(s) are not on the front of your computer case, be sure to get around back. Air flow is critical to your PC, especially for newer machines that have a tendancy to generate more heat. Keeping the dust bunnies off the airfilter grids will extend the life of your equipment.
Defrag the hard drive. As you use your PC the hard disk becomes fragmented--files are broken up into small pieces that are stored at different locations across the drive. The computer can still read the files, but it slows things down.
Defragmenting in easy. Return to the Tools tab under Properties for your hard drive in My Computer where you found the Backup button. You will find another button there named "Defragment Now." Click it and follow the wizard. If there are errors on the drive it is no big deal. Go back to the Tools tab and click on a third button there named "Check Now" and have the wizard automatically fix errors. When that's complete, you can return to the defrag wizard and continue.
Be sure to turn your screen saver and any power-saving features off until the defragmentation is complete by right-clicking anywhere on your desktop and choosing Properties. Click on the Screen Saver tab and choose "none" in the screen saver options. Then click on the Power button there and deactivate the power saving features. You can turn these back to the former settings when the defrag is finished.
Every Six Months
Remove unwanted stuff. Go to your My Documents folder and find anything there that you do not want anymore and delete it.
Then go to Control Panel and choose Add/Remove Programs. If there are software applications there that you don't want or never use, uninstall them.
Then go to Windows Explorer (right click on Start and select Explore) and look under Program Files. If you see folders for a software application that you just removed, delete them. Some programs do not uninstall completely and you have to finish the job manually.
Then open your Web browser and clean out the cache. In Firefox, click Tools, Options, Privacy, and click on the Clear button next to "Cache." In Internet Explorer, click Tools, Internet Options, and click the Delete Files button.
With that done, go to My Computer and right-click on your hard drive; choose Properties and select Disk Cleanup on the General tab. This tool will get rid of a bunch of extra junk that's taking up space.
Clean the registry. Use Microsoft's free RegClean, which is available at your favorite reliable free download site (there are many). It will do a decent job of tidying things up in the registry. Unless you are savy about the registry, do not play around in there on your own--you may mess things up big time.
With all these things done, defrag your hard drive like you do every month (see above). And then, in the spirit of cleanliness, turn your keyboard upside down and rap it a few times. Yuch! What is that stuff?
Finally, open the side of your PC case and use some canned air to clean out the dust (cough, cough).
Following these maintenance practices does not guarantee a smooth-running computer, but chances are you will have far fewer problems than you would have otherwise.