ut3 crashes

my ut3 crashes aswell when im playing online and campaign, it crashes with and without the v1.1 beta patch ,any1 got any ideas? ( i get de-buggers , locks on my pc and sometimes it crashes and comes up with a blue screen with critical error, ive tried running the game through the steam network but same problem, aslo if i have xfire open that closes my game donw and comes up with error reports ,) ill try taking the side of my pc off to let it cooldown quicker but if any1 got any suggestions plz tell me. (also its just ut3 that crashes)