New Server 2012.
Old XP machine. user wants their Documents folder wherever they login.
Enable folder redirection. Advise user to reboot. User reboots. user says "it has spent more than an hour saying 'Applying Settings'". I figure it must have hanged, advise her to repower the PC.
PC cannot boot. If you choose Normal, you get about 5 seconds of the XP logo, then it shuts down and restarts. Choose "Last Known Good Configuration", same results. Any of the Safe Modes ends with "Mup.sys" loading, and then shuts down and reboots.