Hello, i very recently built a gaming pc ( about 3 weeks ago) my first time doing anything like this so please realize I may not understand alot of technical terms, anyway im 2 weeks in and im having a great time playing games when suddenely it just turns off, no warning, no blue screen, nothing just shuts off and boots itself up again so i tried playing another game it did the same thing. The problem persisted for a day and then in the morning the problem was gone so I didn't give it another thought. Fast forward one week and its happening again. I boot my system and when im watching vids or surfing the web nothing happens but when i start playing games and 4 or 5 minutes in it shuts off. I do not think this is a heat issue as I monitor my temps with programs like speccy and coretemps and only goes to 40-55 C when playing graphic intensive games. Here are my specs. My power supply is very new and is 500watts, so i dont feel that is the problem either.
Microsoft Windows 7 Professional 64-bit
Intel Pentium G850 @ 2.90GHz
Sandy Bridge 32nm Technology