On newer computers with Windows 2000 and XP, there is a keyboard shortcut "Windows + F". This shortcut will bring up a search window when pressed once. When held, however, multiple (into the hundreds and even thousands) of search windows will appear. The time held directly correlates with the number of search windows to appear. When held long enough, the computer may crash and may even need a restart. This is something done in many schools to screw around and pull a prank on a fellow, and later on, pissed off, classmate. It also adds an extra shock when one turns off the monitor making an unsuspecting victim.
Teachers are always stumped when they see this dilemma, and usually suggest restarting, thinking the computer just freaking out.
Uneducated users also don't know "Ctrl + W" and "Alt + F4" can be held to very quickly get rid of this problem. However, these shortcuts will not solve the problem if it is held long enough to crash.
Teacher: Why don't you come up to the board and show us this model.
Student 1: *Walks up to board*
Student 2: (Whilst student 1 is at board) *Presses and holds "Windows + F" for an extended period of time, then turns off monitor*
Student 1: *Walks back and turns on monitor, seeing the hundreds of search windows* "Son of a biiiitch, I got Windows F'ed in the A"