The application "exe" file for OE is msimn.exe.
It is possible to have multiple instances of this file running. The usual symptom is that you cannot start OE because there is still a fragment running in the background.
After you've closed OE, do a "Ctrl/Alt/Del" and check whether msimn.exe is still running. If it is, "End Task" and see if the PC shuts down properly.
This is a simplistic long shot and may not solve the problem, but it may help diagnosis. I can't find any reference to the fault you describe; can you give us the exact wording of the error message and say what version of Windows and OE you are running?
[ 02 January 2002: Message edited by: fobotcso ]</p>