I have had this problem for about 4 months now and finally I am sick of it. It restart at random times, but it happens more often when I am doing something serious like a game. I just changed the fan and heatsink on my cpu and did helped, I also changed my power supply, the thing is that when my case is open it restart alot less. I can play for about 2 hours before I get a restart, but when my case is closed I get about 10 to 15 min before a restart. I have no clue what it might be so anything anyone can say is great, and also I did the ram test I took one stick out and then the other and it still restarted. Thx everyone.....