It's very possible that you are generating a kernel mode exception at
shutdown. Try changing your Startup and Recovery options to not
automatically restart after a bugcheck. Also, check your System event log
for any ACPI errors. If you have any, you will want to see if there are
any BIOS updates for your system.
- Bill Curtis [MSFT]
“This posting is provided "AS IS" with no warranties, and confers no
rights.”