Anyone else append something like this to AUTOEXEC.BAT as a kid at school? We were a right bunch of bastards.

  @echo off
  echo FORMAT /Q C:
  echo ALL FILES REMOVED 
  SET DIRCMD=0

https://imgur.com/a/eX4UKLk

There was some memory command you could stick in someone's autoexec.bat that made the machine reboot so it got stuck in an infinite reboot loop until you stopped it using f5 or f8.