XP error

I have had this computer for quite some time now. recently I added some hardware and put it in a new case. then i went on vacation for a month. when i got back i got the linked error message. it keeps comming up at random times and i cant figure out why. the last time it happened i had some friends at my house and one person said he thought it might be an overheated component.

http://img358.imageshack.us/img358/8462/p82112605ww.jpg