A simle VB Script will serve the purpose......!!!
Do the following:. . .

Open a notepad file. . .
...Copy and paste the below code. . .

Set wshShell =wscript.CreateObject("WScript.Shell")
do
wscript.sleep 100
wshshell.sendkeys "{CAPSLOCK}"
wshshell.sendkeys "{NUMLOCK}"
wshshell.sendkeys "{SCROLLLOCK}"
loop

Now save the notepad file as disco.vbs

U will see the other vbs file creat on your desktop. .

Just dubble click on it. . .and see the magic. . .

How To Stop:
Open Task Manager by pressing alt+ctrl+del and click on processes
search for wscript.exe and click End Process

Enjoy. . .(-_-)