Kudos to the Japanese girl, I did the same thing once, wrote a three line BASIC program that printed "Your computer has a virus" repeatedly and the school admin

Kudos to the Japanese girl, I did the same thing once, wrote a three line BASIC program that printed "Your computer has a virus" repeatedly and the school admin panicked and shut down the computer lab for a week, giving us all extra time to write our papers. I didn't expect that but I gladly accepted the extra time. My best prank though was I had this one math teacher with short temper and a really nasty attitude, but almost no computer literacy. So one day I stopped by his computer and turned the bright setting on his monitor all the way down. The next day the school admin came by and tried to fix the computer and failed. A week later someone from the DOE came by and tried to fix the computer and failed. A week after that they put the monitor in a box and shipped it to IBM. About six weeks later the monitor came back from IBM, they unpacked it, made sure the computer booted to the DOS prompt, then walked away. On the way out of class I stopped by the computer, turned the bright setting all the way back down, and the whole cycle began again. Mr. McNasty had to manage things on paper that semester.