"Fortunately", back in the days when I was at school, the BIOS tended to have backdoor passwords that were easily googleable. That stopped working eventually, but then I happened to procure for myself a second-hand school computer which turned out to have the BIOS password still set when I bought it. Short work to then run a tool to read the password directly from CMOS.

I've forgotten what it was, but for all I know they're still using the same password. Oh, the lengths I went to to run linux livecds...