This trick can make ur OPPONENT'S PC SHUTDOWN.read CAREFULLLY its very easy and excellent.
SHUTDOWN OPPONENT'S PC FORCEFULLY.
how it runs - you make a shutdown.exe and make ur enemy run it .

Open Notepad Write Shutdown -S (SHUTDOWN(SPACEBAR)-S)*
Save with name shutdown.bat

Send the save file through yahoo messenger or through mail to your friend.

OK NOW AS SOON AS UR FRIEND OR ENEMY WILL RUN IT HIS PC WILL SHUTDOWN,WITH THE COUNTDOWN STARTING FROM 30 SEC.