I learnt today how to shut down/reboot a huge number of computers en masse regardless of whether or not they're turned on. Windows XP and Server 2003 have a command line utility called “shutdown”. If you pass a /i switch to it, a cool GUI interface pops up. At the top, you can add one or more computers to reboot/shutdown. I generated text file dumps of my computer labs with each computer on its own line. I paste the whole thing into the box, and click okay. From there, I just set the wait time to two seconds, pick a reason for the shutdown/reboot, and click okay. The utility iterates through the list gracefully, and handles any unreachable machines without error. Machines which are inaccessible have their names printed out the command line once the utility is through.