Re: school needs help stopping hackers
With the problems you describe, I think you should seriously ask your school to install CCTV in your computer suites.
At least you'll be able to punish those responsible, if not prevent it.
The kids are accessing the BIOS probably by (you won't believe this) opening the case. Sounds daring, I know. They're probably opening the case and removing the CMOS battery from the motherboard. This makes the motherboard "forget" the BIOS settings, including the password, thus enabling the kids access to the boot sequence, allowing them to boot from CD to install different Windows.
To be honest, why they would want to is totally beyond me.
Master of common sense. If you don't like it, stop reading.