Use a livecd/liveusb. Slax on thumb drive or memory card would do the job

And if you don't have a thumb drive or memory card, then use mepis the livecd.
There's always a strong possibility of being able to bring a system to it's knees for you needs with live media

The college i went to didn't password protect any of there bioses.
I got locked out of my college computer account when i didn't remember my password 5 times in a row trying to remember because they made me change it too often (and the techs were too incompetent to be able to make resetting my password work). So, in a crunch for time on a number of occasions without my eeepc, i'd have to hack a computer with livemedia to get an exam done. Justification is a wierd thing, hacking the college computers is wrong, but it was something i needed to do sometimes to pass my classes when i didn't have all of my resources with me (ie, performing a wrong to fulfill a necessity).
Whoever does password protect there bios is a smart ****er. After the fact not many people will go through the trouble of popping out the coin battery or even know what that would do.
That's my 2 cents, this problem is seriously ****ed. Talk about stepping out of bounds/school property. And possibly the moral implications of hacking something you'd get in trouble for. In this case with this high school, i'd support hacking that doesn't leave a trace (livemedia) so that webcam bull**** doesn't happen.