Originally Posted by DEVIS
If none of the above is true, the best thing, and also easiest, would be to set up a BIOS password. Not easily breakable, unless the perpetrator, after digging up the diagrams from some underground online forum, was able to put together a little PCB with various diodes and cathodes mostly obtainable through your local Radio Shack.
Not sure about laptops, but for most desktops getting around the BIOS password is as easy as changing one jumper on the motherboard. Takes two seconds, as long as you have the computer manual to tell you which one to change to what.