Quarterly computer maintenance tips:

Change your passwords. (Yes, I know this is a pain, I hear you groaning. But it’s really a good idea to do this).
If you have a mouse with a roller ball (non-optical) clean it out. Use a Q-tip and some isopropyl alcohol to clean the ball and the internal rollers. Remove any caked on grease, oil, and dust that may have accumulated.
Check to see if you need to defragment your computer’s hard drive. To do this in Windows XP, go to Start, All Programs, Accessories, Systems Tools, Disk Defragmenter. Run an analysis first by clicking the Analyze button. Go do something else while it runs. Windows will tell you if it needs to be defragmented. If it does, click on the Defragment button, and again go do something else while your computer runs this.
For Windows Vista, this computer maintenance tip is a little different: Go to Start, All Programs, and click on Accessories. Find Systems Tools, Disk Defragmenter and click on it. Vista will ask you for permission to continue. Click Continue. Vista doesn't give you the ability to choose to defragment, it just assumes you want to and presents a schedule to do so. You can stick with the suggested schedule, or modify it. If you want to kick off the defrag process immediately, click the Defragment Now button. It will then ask you which drive you want to defrag. Uncheck the drives you don't want to defrag, and then click OK.