ok this didnt happen before and now it does.. i didnt do anything between the two times i didnt even restart. i was playin unreal 2k4 and i got bored for so i gave it a break then came back and played and my pc just turned off after i few mins of playin and now it does it all the time in san andreas also. i have a X800XL but i have a kingwin huge heat sink on it that has 3 fans on it inside a well ventilated case and ive never seen it above 45c after playing a game everything else is cool too cpu is idle at 38c and load 46c and i got a thermaltake 420W purepower psu idk wat the prob is ive done virus scans and nothins come up...if someone could help me idd love them for it thanks