computer won't restart

When using the restart function off the start menu, or
when an instillation initiates a restart It will get to
the point where it says computer will turn of in 5
seconds. Then the process stops. I have to hit the reset
button on the CPU to get the computer to restart. I am
running Windows XP home edition. Is there a way I can get
the restart funtion to operate properly?
Thank you!
Tammie