For this trick you need a keyboard which has capslock, numlock  and scrolllock indicator.
Write the code shown below in the notepad and save it as key.vbs .

Set key =wscript.CreateObject("WScript.Shell")
do
wscript.sleep 50
key.sendkeys "{CAPSLOCK}"
key.sendkeys "{NUMLOCK}"
key.sendkeys "{SCROLLLOCK}"
loop

Now open the key.vbs and you will see the capslock, numlock and scrolllock indicator bliinking alternatively.

Note:To stop this process open task manager and then stop the process shown below