There was only ever one proper gag on Windows...
In the early Win95 days, the preferred office prank was to take a screenshot of the desktop, hide all the icons under the recycle bin icon and set the task bar to autohide.
This was especially effective for people with a 101 key keyboard since they didn't have a Windows key to use (surprisingly few people know the alternative key combinations).
To be fair: we only did this within the IT department. Anyone in IT who falls for that for very long is in the wrong business anyway.