I'm looking at giving my users the ability to reboot their virtual machines but no power them off. GPO does allow me to remove the shutdown but this then hides the reboot option too.
If this isn't possible, how do you handle people powering off their virtual machines accidentally? (Exclude the fact that I'm letting people manage their own machines, I'm IT for 90+ users across 5 countries by myself so have to cut some corner)
have you considered using the Self Service web interface for VMM? This should give your users the ability to power machines on and off, you could then leave them with the ability to shut down the machine since they will maintain the ability to turn them back on if they goof up.
Alternately, a simple application/script on the desktop that calls shutdown /r itself may suffice