First You will need a PC,then go to start at the lowest left corner of the screen.
Step:2,Search for CMD or Command Prompt.
Step:3,Open it(CMD) and type "color a" for green color of text.
Step:4,Now type "cls" for clearing the screen
Step:5,Now type "netstat" for other people's PC IP Addresses.
Step:6,Now type "shutdown -i" for opening Remote Shutdown Dialog.Then Click on Add and type in the IP Address of victim and click Ok.Now in the next box select what you want to do with the victims PC(only includes Shutdown,Restart,Anotate Unexpected Shutdown).Now in the next box tell for how much time do you want to display the warning.Now on the next box do nothing.And on the last box type in the message you want to give to the Victim as a Warning and click on Ok.To cancel the shutdown type "shutdown -a" in the Command Prompt(CMD).Below is my video for this Purpose.