Even though it is not often advertised by Windows, or maybe because my Windows 98 habits die hard, I like to schedule my work XP machine to reboot weekly. Here is how it works. (Note: if you have 2000, you will need to install the resource kit for this to work)

1. Create a batch file in your C drive (I call it "auto_reboot.bat")
2. Add this line: shutdown /r /t 60 (this will make the machine reboot after 60 seconds)
3. Create a scheduled task to run "C:auto_reboot.bat" at whatever time works best. Just remember, any unsaved work will be lost during the reboot, and if for any reason, you are at the machine while it is about to reboot, just enter "shutdown /a"� at the command prompt to abort.