shutdown.exe -s -t 60, the system will shut down in one minute.
to make it one hour, just input shutdown.exe -s -t 3600
to cancel it, just open Run by hitting “Windows Button +R” or by just choosing start >run
Shutdown.exe -a
learn from
http://sasicbit.hubpages.com/hub/Autoshutdown-your-Computer-after-a-specified-Time
