Scenario:

You wish to restart the machine “MyServer” from another computer on the network. The usual routine is:

shutdown /r /m \\MyServer /t 0 /f

If shutdown.exe returns an ‘Access is Denied’ error, then you either didn’t run the command with elevated privileges, or “MyServer” is unable to validate your credentials. If so, run the following command in an elevated prompt:

NET USE \\MyServer\IPC$ MyPassword /USER:MyUser

Where MyPassword and MyUser are appropriate credentials for an administrator account on the MyServer machine.

Once it’s run, you’re returned to a prompt and the shutdown command above should work.