I have Sony VAIO desktop PC. It is about 4 years old.
When I install a program update that requires a REBOOT, nothing happens. From START choosing Shut Down, nothing happens. From TASK MANAGER, nothing happens. If I use Task manager to Log off user then chose shutdown/restart it works.
May be your registry is all jam packed.For that you need a registry cleaner.
If it does not help then it is better not to use any software for the purpose, rather search in google "XP trick/windows tricks/vista tricks+faster shut down".that way you may get info about how windows shuts down and what to modify manually(may it be in group policy or the registry etc.) to solve the problem.
Pardon me if I my instructions don't help.
Navid Mostafiz
September 2008
Automatic Answer
While you wait for answers, we may have found some information which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix desktop pcs.