Out of nowhere I started getting a BSOD. It seemed to be pretty random but it was always the same BSOD (Machine Check Exception: 0x0000009C). After reformatting, reinstalling WinXP, and a lot of troubleshooting, I finally isolated the issue. If I had my second harddrive installed, I would get this BSOD.

I initially had 4 HDDs installed:
C: (SATA 1)
D: (IDE 0 0)
E: (IDE 1 0)
F: (IDE 1 1)

I tried moving around the D: drive to different IDE channels and I would still get BSODs. The drive worked fine in Safe Mode. I tried it in other computers and it worked fine and there was no data corruption or surface errors. As far as I can tell the drive is perfectly fine. (All this time the drive had been using the drive letter D: as I set it manually in Disk Management).

Anyway, since I needed that drive active, I purchased a new SATA drive to replace it. I just got it today and installed it. The drive appears to be fine. However, the second I used Disk Management to assign the drive the letter D:, my system got a BSOD. So I disconnected the drive and on a whim decided to try assigning the drive letter D: to one of my other drives. Almost immediately my system gets the same BSOD. So I tried setting another drive as D:, and again a BSOD.

As long as I do not have a harddrive assigned the letter D: my system is fine. So I've set one of my DVD-RWs as D: and my harddrives use the letters after that. I have no idea what is causing this but it is frustrating to say the least. Why am I no longer able to have a harddrive assigned the drive letter D:? I have had a D: harddrive for over a year without issue, why is it an issue now?

I've confirmed the issue is not with my PSU, RAM, CPU, video card, or any other expansion cards. The only thing that has not been replaced is the motherboard. Which I highly doubt is the issue as the drives all function perfectly when not assigned the letter D: and even work fine in safe mode when the drive is assigned D:.

I have tried disabling EVERY non-MS service and every non-default startup object. Can this be a driver issue? Or software issue? This honestly makes no sense to me. Anyway, I'm too tired for this at the moment. Thanks for any ideas, suggestions, etc.