I have XP also. Clear out your cookies and check your number of programs running like Nina suggested. Instead of just unplugging your computer (hard shutdown), use CNTRL-ALT-DEL. It will give you a box listing your nunning programs and which ones you want to end. And also check which programs open on start-up. Shut down your computer every night and start it in the morning so you revert to your default set up.
Hope this helps
Artemis
