How to remotely power off a PC on the LAN

Chandler, Arizona Computer Repair: In winXP click Start>run,type shutdown -i to shutdown my pc, pls help me to shutdown other pc in lan network.

In winXP click Start> run,type shutdown -i to shutdown my pc, when i click add>browse a note: “The Directory Service is currently unavailable” appear. Help me to shutdown other pc in lan network