Click Start, then All Programs, then click Accessories, and click Command Prompt. Else just search for cmd and run.

Type “shutdown /i” to display the Remote Shutdown dialog box.

Under Computers, click Add button to enter computer names, or click Browse to open the Find Computers dialog box to locate the machine name on the network.

Next under “What do you want these computers to do”, select Restart or Shut down.

Select the appropriate reason for the restart or shutdown from the list. Then click ok and let it run.

Another way to do this is run the following command from dos prompt.

shutdown -m \\computername -s -f -c "rebooting soon in 20 seconds" -t 20