I ran into this today, but my case was a bit different. I got into the recovery console, found out that auotchk.exe was in fact missing. I replaced it, but it just meant that it got to rebooting even quicker (just before the Windows login prompt would display in the classic style). Turns out my partitions got misordered. C: (windows boot) became D:, D: (programs) became E:, E: (just plain ol' disk space) became F: and F: (5GB swap file) became C:. I don't have Partition Magic, so I got to running ptedit.exe, the drive types were 06, 07, 07 and 0F, but I also don't know which partition is which, aside from the fact that 06 has a boot record so it's the old C:, now D:. Things are worse now, after running ptedit, the now D: and F: partitions are listed as [Type Unknown] in the recovery console using diskpart, and appropriately, the PC doesn't boot at all now, having no MBR. Checking back in ptedit, everything seems to be the same as it has always been. So my 2 questions: - Would mislabelled drives be cause enough for the machine to restart when Windows attempted to boot? - Can Partition Magic solve my current problem?