Originally Posted by Rubber314Chicken
alt+f4 makes your screen look cracked.
Well it's not really a hack more of a prank.
Well a personal favorite is to hit print screen on the desktop, paste that in any editor.
For example Microsoft paint.
Shorten the image a bit from the bottom, so it removes the toolbar.
Then make that image the desktop wallpaper.
After doing this, right click on the desktop > Arrange Icons By: Then un-tick Show desktop icons.
This will stay like this even after restart, confusing the user as they click the icons (really there wallpaper) and nothing happens.