Hi, Chaz.
First, check out Jim Eshelman's site, as Bareill recommended.
If that doesn't work, your computer may be hitting an error in the process
of shutting down and, as instructed by default, rebooting. Go to System
Properties | Advanced | Startup and Recovery Settings. Under what to do in
case of System failure, uncheck the box that says Automatically restart.
Next time, instead of rebooting, your computer will probably halt with a
BSOD (Blue Screen of Death) full of cryptic codes. You will still need to
reboot by pressing the Restart button, but you'll have all the time you need
to study that BSOD. If you can't figure out what it's telling you, post the
error codes VERBATIM into your next message and some guru here (not me!) can
probably point you in the right direction.
RC