I had a strange problem today with my Windows 2003 64-bit server: it rebooted itself! After it rebooted, I logged in and bang: BSOD! Again and again.
I tried booting in safe mode and I noticed that the system was taking a few seconds to load ACPITABL.DAT. Having no idea what that file is, I did a little search and didn't found answers to my exact problem but found enough info to tell me that it was some kind of hard disk/drivers issue.
I have a couple of external USB drives connected to that server for backup purposes so I decided to turn them off and then restarted the server. Bingo! I was then able to log without problems. I then turned on the external drives again, without problems and no files damaged.
I was able to fix the problem but I have no idea what was the problem or what caused it. Go figure!