GameSpy have posted an article titled, How to Fine-Tune Your Gaming Rig, in which they offer some tips and tricks to get your PC in top shape when it starts to grind to a halt:
"It's one of the hardest things to do, throwing stuff out. Hey, you never know when you might want to play that game again. But you know what? You've got to do it some time.
So, just how much have you got there sitting around taking up space?
The easiest way to check for all those programs that you've forgotten about is to visit your Windows Control Panel. The handy "Add or Remove Programs" applet keeps a list of all the programs that you've installed, lets you know how much space they're taking up, and it even keeps tabs on how often you've used them"