Try system restore if none of the registry fixes work for you. I know there is another speed up tweak that could be causing the problem:
This reg tweak disables your pagefile from being cleared. It might not be a good idea if you keep a lot of passwords stored on your computer.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management
Change the value of ClearPageFileAtShutdown to 0. Close the Registry, and restart your computer.
This tweak deals with setting the amount of time Windows will take to kill open applications on shutdown.
'WaitToKillAppTimeout' value to 20000.
changes the same settings, this time for all users on the system:
'WaitToKillAppTimeout' value to be 20000 and
'HungAppTimeout' value to be 5000.
Hope it's some help!
Edited by crazyguitarchik, 30 September 2005 - 12:06 PM.