We got exactly the same situation after the following operations:
- Restore of a previous XP onto the same spot
- Installation of an XP-SP2 from scratch: hang on the first reboot from the xp installer after itís finished with the copying of files
- Replacement of the disk by another disk and Installation of an XP-SP2 from scratch: same hang as above
Oddly enough, the installation of XP-SP1 was successful and things appeared to work properly. When we successfully installed the MS upgrade patch to SP2, we ran into the same hang at startup.
Another symptom : disk copies using Acronis Disk Director Suite are unusually slow: the copy of a 4.5GB partition from one disk to another required 1 hour and a half!