Hello Spike

Welcome to PCHF
If you have done a full format and restore then the first thing I would try is taking out pieces of hardware and try running the computer. For example, remove the video card and try running without it (if you have onboard video). If you don't have onboard video, try testing another video card if you can. You can try removing all but one stick of memory and try each stick of memory individually. Also try removing all the other peripheral devices if you have any like a pci modem, network card, etc.
Also, go to the website of the manufacturer for your hard drive and download their free diagnostic tool. Use it to create a bootable disk and run a diagnostic that will test the integrity of the hard drive.
If all that comes out with no solution and you continue having the problem, then you probably have a problem on the motherboard. It is possible that it is a faulty power supply, but unlikely.
Let's go from there
