|Take the cover of the case and locate the CMOS Clear pins. With the power removed move the jumper from from one set of pins to the other for a few sends and then return it to its original location.|
This will clear the CMOS memory and allow you to enter the BIOS. You will need to re-enter BIOS settings as they will also be cleared.
However this assumes that it is in fact the BIOS Password that you are talking about. If this is a laptop and it is the hard disk password then you will need to contact the manufacturer with proof of ownership.