I think its a matter for implementation in the guest OS, I mean to run a shut down & power off from inside the guest, and that should work.
Virtual PC doesn't know how to shut the guest down - at least it doesn't for all possible guests - and the guest OS may not include any built in mechanism to respond to shutdown requests from the hardware, so a Virtual PC initiated shutdown is likely to either be ignored, or end up as being the same thing as simply killing the virtual PC process - and that will potentially corrupt data in the guest OS same as pulling out the plug at the wrong time on a "real" computer can.
Regards
Rob Moir
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