ok just save this image to your laptop or computer.
Step 2: Step 2
now set the cracked screen as your desktop background. right click the screen and go to view : show desktop icons. click show desktop icons and the icons will dissapear giving the look of a cracked screen.
Step 3: Step 3
call someone to the room and look worried and tell them the screen has gone. watch them flip out.then just right click the screen again click view: show desktop icons to reveal the icons. tell them they have been pranked.