Basically my friend's (which is not in the country) computer is having problems with constantly restarting so his parents brought it over to me. It usually restarts several times during boot up, sometimes restarts during idleing. I don't know much about computers hardware wise but I am guessing the power supply may be too weak for it. The PC has an nvidia 750W supply and I have seen that min is 1000W for that video card + other hardware of equal level. There is also an Intel Core 2 Duo E8400 on board. What I tried is disconnecting the dvd/cd drive, the front usb+audio+mic ports (dont think this matters) and a couple back SATA ports. After I disconnected the stuff, I still noticed PC restarts quite frequently. So my second guess is something overheating. Everything in PC is pretty cool, only the video card temperatures look a bit high (first GPU is around 65-78 celcius while the second is much cooler running around 50-60 celcius). Might it be over heating? What I tried to do is setting the 2 fans (top and side) to low speed (because I was going to sleep) and the computer restarted within maybe half an hour. So I put them both to max. What else can be the problem? How can I solve this? Is the power supply too weak? Are the temperatures too high? BTW The PC worked fine for like a year for them... Do powersupplies age and become worse?