Cool Windows XP tips & tricks: How to speed up your PC: Display settings

By disabling unneeded visual effects, you can speed up your windows xp pretty much.

How to change display effects:

Go to control panel from the start menu
Open performance and maintenance
Choose adjust visual effects
In the window that appears, uncheck any effects that you don't consider necessary, or just choose "Let Windows choose what's best for my computer"
Hit OK and you're done!