Computers... First if you don't have 3-4 Gig of memory, get some.
- As someone mentioned, run a full scan at least once a month. AVAST and Kaspersky are the best I've found. AVAST has a free version, Kaspersky just has a trial version (I pay for it).
- Uninstall all the crap software you don't need: - Control Panel > Uninstall(XP) Programs&Features (Vista)
- Run Disk Cleanup and Disk Defragmenter... All Programs>Accessories>System Tools...
Start the Defragmenter before you go to bed and let it run.