Well, here's the thing. It started restarting randomly running windows. It started restarting as soon as windows loaded. Made me think virus. I booted into safe mode, restarted on its own. I underclocked the psu, booted safe mode, it worked. I booted into regular to get it going for my parents/brother while I go to college for the week. It seemed to work but then it started restarting again on them. I unhooked the 80 gig hd, only had a 20 gig hd that i formated, fresh install of windows ME. During the install it restarted on it's own when it asked to name the computer, but after it restarted it went though it. No it wasn't a restart it was supposed to, the I was blinking and as I was about to type it restarted. I loaded up windows, installed graphics drivers. They worked. I then was going to hook up the 2nd HD to make sure everything was there. Powered down, hooked it up, It restarted as I opened windows again. I have it sitting idle now just running off the fresh install of windows with the 20 gig Only running. Would it be software? virus? Or hardware? cpu or psu going bad? What would I check? Fans are working. Cpu temps seem normal in bios.

I underclocked the psu, meant to say underclocked the cpu.

sounds like a classic symptom of a bad power supply. I would disconnect everything except the board, graphics (on-board if possible), PSU, keyboard, cpu, and 1 stick of ram. Boot into the bios and see how long it runs before rebooting. larry

I put in a fresh power supply and it didn't fix anything.