This is Only for prank actually it does not make any harm to your friends computer.
Below are the steps you have to perform to make prank on your friends.
Step 1: Open you notepad or any text editor installed on your computer.
Step 2: Copy the below code to your text editor.
echo WARNING VIRUS HAS BEEN DETECTED
echo System check
echo RAM - Corrupted
echo Norton - FAILED
echo Virus infecting: ****-****-****-8894
echo your hard drive corrupted
echo Starting to reboot hardrive.
echo Do not attempt to quit.
echo Restart after 10 minutes approximately.
start Internet Explorer.bat
Step 3: Save your file now with any name with extension .bat
Step 4: Now send it to any friend through mail. When he/she will click on this file then this batch file will executed automatically.
You can try it on your system. Its not any harmful virus. It just a prank.