Rebooting Continues

Left the desktop off last night and while I was at work today. Still rebooting randomly. Thought it might be some corruption on the hard drive still, reinstalled Windows XP 64-bit. Still rebooting. Thought it might be Mozilla 1.7 RC2, downloaded older versions, downloaded firebird, still rebooting. Ok, its the power supply i decide. Switched the power supply from another pc. Still rebooting. Ok, the power supply is not powerful enough for the AMD64 and Radeon 9800 I decide. Unplugged some extra fans, the cdrom, floppy drive, disconnected non-powered ribbons. Still rebooting. At this point I’m getting worried. Tried reseting the Bios. Tried flashing the Bios. Still rebooting. Popped in a PCI Mach64 video card and took out the ATI. Didn’t reboot. 16 colors, but it didn’t reboot. So I think its the video card. So I pop in my Radeon 7000 (AGP) that I remembered I had. The damn computer reboots. So maybe its not the $300 video card, maybe its the motherboard. At this point I’m tired and confused. I’m currently reloading Windows XP 32-Bit so I can use more than 16 colors on my Mach 64 video card. If this system is stable on that I think I can assume its a video card/AGP slot issue. Hopefully I can pin that down and get a warrantied replacement.