I hope my explanations make some sense -- please ask for clarification if they don't.
I had a computer running Windows Vista (Ultimate, 64-bit). All was well! Then one day there was a nasty power surge at the office, and it died. (We didn't have surge protectors at the office, unfortunately. I assumed our lines were conditioned elsewhere, or was not an issue here. Oops.)
After some testing, it was determined that the PSU, motherboard, and RAM were bad.
While waiting for new hardware to arrive, I put my hard disk in a spare PC which had identical parts (mobo/CPU/RAM/PSU/video). Everything worked perfectly. The only way I could even tell it wasn't my computer is because Vista asked to re-activate itself with the new hardware, which worked fine, too. So the hard disk seems OK.
Then the new parts arrived. The old motherboard model is no longer manufactured, so it's a new one with the same CPU/RAM/videocard/etc. slots. The PSU is also new, while the RAM I'm using is from the spare PC mentioned above.
When I put it together and tried booting with my old hard disk, it starts to boot Windows, and then (fairly early in the process) gives a bluescreen and immediately reboots (so I can't see whatever the bluescreen is trying to tell me). I tried "safe mode", which also bluescreened. I tried booting the Vista DVD and running the repair utility, which found a Vista install, confirmed that it would not boot, and, eventually, declared that it was unable to repair it.
I installed Vista fresh on a new hard disk, with the new mobo/etc., and it works perfectly. (That's what I'm running now.) I've also booted a Linux CD here, which ran great, and I've run Memtest86+ for a while, which found no errors. So all the hardware apart from the old hard disk seems OK, too.
I don't think the problem is with my old Vista hard disk, since I used that with another mobo/CPU just fine. I don't think it's any other part of the new hardware, since I'm able to use it (and test it) with no trouble. It's just the combination of my old Vista install plus the new PC hardware that's not happy.
I can get my data off my old hard disk and onto my new hard disk, and reinstall my apps, but it would be nice if I could fix things so I could continue to use my old hard disk as before.
The latest hypothesis I've heard is that Vista had trouble with the new hardware (i.e., motherboard), but we have no idea what to do about that (except Safe Mode, which didn't work).
Suggestions? Hypotheses for what's not right about this combination of Vista install and motherboard?