My computer started to restart randomly recently. I have a Nforce4m-a V.3 mobo (I just took it back to the shop and got it replaced but the problem persists), Athlon64 4200 x2 processor, 2 x 512 Kingston Ram + 1 x 1gb stick. Ati Radion x850 Graphics card. Windows xp media centre 2005. Ive had the computer for about 3 months now, I built it myself. In the past week its started to have a seriouse problem of randomly restarting. At first I thought it was just in grphicly intensive programs such as games and DVD's but it also restarts randomly in desktop and web browsing. As Ive said I just changed the mobo for a new one, same model. This appears to have made no differencce. I thought it must be the mobo because since ive had this mobo every so often theres been a beep from the system speaker. I havnt heard that since it started to restart and I read in a forum someware that that indicates the mobo overheating (couldt find any mention of this in the manuel though). Ive rotated beetween the different ram sticks and they have madeno difference. The problem has become more seriouse since I upgraded to media centre, however I have clean installed twice to no avail. The computer did show similar symptoms after I got a virus, this virus caused the computer to retstart contunuously, I managed to system restore which seemd to help however it still restarted very occasionally, now it does it after beetween a few minutes to an hour. Any help would be greatly appreciated. I'm at a total loss with a computer that cost me around 800 pounds to build rendered compleatly useless. Thankyou.