This is a simple prank I learned(and was the victim of) when I was 8. All you need is the victim's computer, and a post-it.
Step 1: All the Steps.
Ok, first, you get a computer mouse. Wireless, or, wire-ful. Then you get a post it. you cover the little shiny LED hole with a small post it.( make sure the post-it doesn't stick out.
Step 2: Results
When the victim turns the computer on and tries to move the cursor, then, ironically, it will not move. (Duh). The victim will try frolicking with the keyboard, or even shuttihg the computer off,(with the button) or check the cable. The victim will last check the mouse before he/she figured out it was a prank. XD
Step 3: Credits
Pics: computer: clipartof.com
Prank: 7 years ago: my friend, Will