Pressing control+c on the wrong keyboard, in the wrong terminal window, connected to the wrong server: the ultimate sign it's time for bed. Just as soon as I do a bit of troubleshooting; I seem to have broken "sudo shutdown -h now" on this Debian machine. It says:
"sudo: The term 'sudo' is not recognized as a name of a cmdlet, function, script file, or executable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again."

I wonder how I managed to break sudo?