I just purchased a AMD 64 4000+. I also run a K8U-939 motherboard with 1048 RAM. As soon as I finished putting it together I transferred my old hard drives (80Gb & 40Gb) into this computer and reinstalled Windows XP. I purchased an Okia 450w PSU. I run with NVidia GForce 5700U (soon to be an X850 XT PE). As of the last 5 days at least once a night my computer will shutdown and WILL NOT restart for a couple of attempts. It always seems to happen during BF2 or SWG. What is the deal?