Windows doesn't respond to remote shutdown or log off

What:

Windows XP/Vista/7

Problem:

System is stuck in the process of shutting down or logging off and you don't have physical access to the machine.

Solution:

Download pskill.exe from http://live.sysinternals.com/
Kill winlogon process, it will instantly restart computer.

pskill.exe \\192.168.1.10 -u "domain\administrator" -p "password" winlogon