Location: Somewhere between broke and racing, closer to broke.
Have you reseated all the hardware like 01WhiteCobra suggested above? Not completing the hardware inspection indicates a hardware problem. Remove everything except the essential items if you have add in sound card and NIC. Disconnect all but 1 CDRom and the main HDD and try again. Bet you have some bad hardware somewhere. How recent are the components, esp. the system board?