I've been having this problem for a while now. Recently it's getting a bit worse and I can't handle it. At random times my computer will just lock up, sometimes after 20 minutes of being on. all I can do is hit the power button after a crash. I'm not sure what's causing it. It's something hardware related, because I had this problem before and after a full format. It has been suggested that it is a problem with my PSU, maybe it's faulty, or something happened to it, and it's causing these crashes. I've left a temperature monitor running, and when it crashed, it was at a normal temperature, about 47 C. A basic rundown of my system is: Asus K8V deluxe mobo, amd athlon 64 3000+, gainward geforce fx 5900, 1024 of ram, one 80 gig harddrive, I can't remember how many watts my PSU is... I'm thinking 420-450... not quite sure how I can figure out for sure, I've looked at it, can't really tell. I've tried different things, I've tried rewiring my system, checking for faulty ram, drivers, bios, all that stuff. Any ideas? Any way I can test my PSU? I want to make sure it's the PSU before I buy a better one... Thanks in advance!