Blue Screen of Death

Why do I keep getting the ole blue screen of death on windows 2k pro? I have formatted and formatted and before I know it there it is again. I have installed any other programs one at a time with in a day apart to try to see if any of them is my problem, But even with no added programs I still get the well you know my death certificate. my pc is a packard bell 300 with a cyris chip, I have installed new Memory ram, new hard drive, have a voodoo 3dfx card, I have not been able to get any detailson the blue screen it goes by so quickly, then its reboots it’s self.
can anyone help me?