How to force Windows Server 2003 to restart

Try instead:

shutdown -r -f -m \\hostname -c "Comment goes here"

That's a bit drastic, but I've had the need to do that in a very similar environment to what you describe. I also open a cmd window and start a ping -t against the server to watch when the IP stack goes down and comes back up. This is a very useful indicator of activity when you don't have physical access to the server (or are too lazy to get up and walk over to it).

EDIT: (based on your comment) Ok, do this first and then try the above again (or restart it as normal if this works). See it that gets you farther. The -a will abort a system shutdown.

shutdown -a -m \\hostname

Is anyone logged interactively e.g. via VNC or an autologin? I've seen this occasionally when something hangs in the interactive session. Typically this happens after the VNC and TS servers have shutdown, so there's no way to get in and kick the server! These days I insist all my servers have a DRAC card (on an HP use the iLO card) so I can hard reset them remotely if I have to.

JR

Does this help:

http://support.microsoft.com/kb/930045

A way to test this would be to create a scheduled task to restart the server in (e.g.) 5 minutes then log out. That way there is not terminal servivce session active when the restart happens. If the restart now works normally the above may well be the reason.