If your machine is hung up (powered on but remote desktop not responding), remote reboot may help get back up and running.

Remote Reboot Microsoft Windows
Shutdown /m <machinename> /r /t 00

/m          specifies a remote machine to shut down (your machine name)
/r            reboot
/t 00       specifies zero wait time

This works from any Windows machine where your account has access (usually in the same local domain or forest).  Remote Administration and Windows Management Instrumentation firewall exceptions must also be enabled on the remote computer.