hey this is a trick for fooling and freaking off your friends....

just open notepad and type the exact code in the window.

@echo off
msg*  warning!your computer has been hacked!
msg * Warning your computer has detected a virus.
msg * To remove the virus click OK or close this box
msg * Your Hard drives are now being formatted
msg * Please wait ...........
msg * you have been made a fool .. lol

save as dangerousvirus.bat and run the following batch file in victim's computer.