Problem playing full screen games

I am running Windows XP SP2 and every time I try and play a full screen game it plays for a few seconds then it kicks me out to the desk top. I used to be able to play these games and I have no idea what might have changed to cause this. I will say that I always have American Online running in the background as well as AIM, and Weather Bug. Any advice would be greatly appriciated.

 

what are your system specs (specifically your vidoe card?)

what games are you playing? (if they are old, a high resolution/ 32-color mode may not be supported)

what is your desktop resolution?

 

After turning off everything I had going one at a time I figured out that it was a program that I always have running 24/7 called Folding @ Home its basicaly like SETI @ Home but it works on folding Protein to help do research into curring desiesses (sp)