I would also check the to see what's running at start up. It's amazing how many programs feel it's their right to add an automatic start up with Windows.
Click the Start button, then Run, and type msconfig in the box then hit enter. Click the Startup tab and see what has a check mark. XP really doesn't need much running. If in doubt, Google the Startup item.

I started out with nothing & I've still got most of it left
M60 VP160 QS8 EP350
M22 VP100
Algonquins