I'd boot the hard drive maker's test program and see if the hard disk passes the tests.
I am running Windows XP Home Edition on a Pentium 4 3.0 Ghz, 2MG cache with an intel D945GNTL Motherboard and 160 GB hard drive and 1 GB memory.
I had the computer on yesterday and all was fine. I left it running (with windows up), and I went back to it 4-5 hours later and there was nothing there. (At first I thought it was in sleep mode, but the mouse would not awaken it--normally, it will kind of sleep when I'm not active for a while and I am then prompted to reenter my admin password and windows is restored to the point were I left it previously). So, I was forced to restart the computer at the switch and now it cycles on, I see it searching for the rom drives and then it stops and windows won't load. Can you help?