9. Fake a Desktop with Screenshot Wallpaper
Freak out your co-worker or family member by faking out their Windows desktop with an unclickable facade: Take a screenshot of their current desktop, then set it as the desktop wallpaper. Hide the actual taskbar and disable desktop icons (right-click the desktop and choose "Arrange Icons By" and uncheck "Show Desktop Icons.") When your victim returns to the computer, watch the futile clicking begin.