unexpected_kernal_mode_trap

I just installed win200 on a standalone computer and it keeps crashing with unexpected_kernal_mode_trap at address 0x0000007f,0x00000000, 0x00000000, 0x00000000, and then it copies to disk and reboots. What could be the problem. I installed servicepack 2 and ie 6.0. neither helps. Can anyone out there help? Thank you.