WSH 2003: Unable To Shut Down

My Windows Home Server box hangs near the end of a shutdown and I
have to pull the plug to finish.

It gets through the "Windows is shutting down" dialog, but hangs
on an empty blue WSH splash screen.

OTOH, if I choose "Restart" instead of "Shut Down", it behaves as
expected - re-starting after the "Windows is shutting down"
dialog finishes.

Is this difference telling me something?

Greater minds that mine have suggested a driver as the culprit,
but I have no clue how to go about proving/disproving that
hypothesis.

At startup, WSH throws a "One or more drivers failed to
initialize" message but, of course, it doesn't give any clues as
to which one.

Found a few items under Device Manager with yellow question marks
and disabled them, but the message and the shutdown problem
persist.
--
PeteCresswell

Hi PeteCresswell,

Typical causes of shutdown problems,
Faulty or incompatible device drivers.
System services that either do not respond correctly or send busy request messages to the system.
Faulty or incompatible programs.

Try following:

Use Task Manager to identify the cause of the shutdown behavior.
Undo any recent changes to the computer.
Use safe mode to identify the cause of the shutdown behavior.
Confirm that the computer's complementary metal oxide semiconductor (CMOS) and basic input/output system (BIOS) settings are correct.

remove either the last driver or the last program that you installed, and then shut down and restart the computer to test whether the computer shuts down correctly.