Computer auto reboot.. help

[Xellos2099]

OK, so i leave my computer on last night to do something, nothing unusually, however when I wake up this morning, the computer is off somehow. I try turning it on but no responds. I try turn off the psu switch and on and it work. However, whenever I try boot into window it auto shutdown. My friend suggest virus so I got in safe mode and try scan. Same thing, auto shutdown, but then somehow I manage to get in normal window. I am able to use it for 15 minute before it auto turn off again. Think the psu is causing the issue? Using cosinar 650, 2500k sandy and 7850 taita

 

[mfenn]

Look in the Event Viewer to see if you can find any sort of logs about what caused the shutdown. The time of the shutdown should be fairly apparent because there will be a large gap in log entries from when it went down to when you turned the machine back on.