Sometime it is necessary to reboot (or shutdown) windows server. Under UNIX or Linux you can use reboot / hal t/shutdown command via cron jobs or at command. But, when it comes to Windows server there is no built in command exist. Only Windows 2000 Resource Kit offers shutdown command line utility.
However, sysinternals has nifty utility called PsShutdown. It is a command-line utility similar to the shutdown utility from the Windows 2000 Resource Kit, but with the ability to do much more. In addition to supporting the same options for shutting down or rebooting the local or a remote computer, PsShutdown can logoff the console user or lock the console (locking requires Windows 2000 or higher). PsShutdown requires no manual installation of client software.
Thanks

More Details
Animated Online Promotional Video