For a few months my home built pc would shut down will playing a game, I bought some thermal paste and it worked for a while, then it started shutting off again. My GPU and CPU temps were never dangerously high, and I ruled out viruses.
Nvidia GTX 550 Ti
AMD 760K 4X 3.8 GHZ
500 Watt PSU
Nvidia GTX 550 Ti
AMD 760K 4X 3.8 GHZ
500 Watt PSU