Hi
For shut down problems I ensure that
all my boxes are empty.
And I have made a desktop shortcut to shutdown, just in case.
You can use the command line.
C:\WINDOWS\system32>shutdown
/i Display the graphical user interface (GUI)
/f Force running applications to close without forewarning users.
and lots more.
Hope this helps.
Errr Ironfly beat me to it with a comprehensive answer, but hopefully mine is prettier
)