1: Take a screen shot of your victim's desktop.
2: Save the screenshot completely unedited.
3: delete ALL of the icons from the desktop and minimise the system tray.
4: set the screenshot as the victim's desktop picture.
5: Laugh as they click at icons and the start tray but nothing happens.
6: Flame me as this is a repost of a repost repost, but I can't search.