Shutdown and restart/reboot Windows from the command line.

:: To restart (/r) the machine and force (/f) users to log-off:
shutdown /r /f

:: To restart (/r) the machine and force (/f) users to log-off and provide a comment (/c "comment") for the shutdown:
shutdown /r /f /c "Rebooting to apply latest updates."

:: To restart (/r) the machine, force (/f) users to log-off, provide a other-planned reason code (-d [u] [p]:xx:yy) and a comment (/c "comment")
shutdown /r /f /d P:0:0 /c "Rebooting to apply latest updates."

:: To restart (/r) a remote machine (/m) (, force (/f) users to log-off, provide a other-planned reason code (-d [u] [p]:xx:yy) and a comment (/c "comment")
shutdown /m "\\hostname" /r /f /d P:0:0 /c "Rebooting to apply latest updates."