I looked up the downloads page for your motherboard Biostar USA
(make sure that that is your motherboard because you don't want to get that wrong).
You'll want to download P4M9M614.BSA, and follow the instructions (see the link How do I update my BIOS on that page). It doesn't matter what OS you use since the OS isn't involved.
However for me when I try to download either of those files, I get an error that the folder can't be found - hopefully you can have better luck?
Anyway, without having your BIOS I can't really tell you where the password function is, but it should in there somewhere. Try looking in your motherboard manual to see what it says there - it should have information on every function in the BIOS.