Send WinPopUp messages trought the net
I don't know if you will know the program WinPopUp of Windows...
It allows to send small emergent messages to other computers of the net.
If you don't know it... test it, you must only execute it and it will remains listening.
If a message arrives... it emerges to show it to you.
With the function that I put you in this trick, you will be able to send messages of this type that will activate this program (WinPopUp) in another computer connected in your net.