I don't know if what you want to do is legal or not, but I found myself in the same situation once so presuming what you are doing is legal I will help you. In the command prompt type 'debug' and hit enter. Then type o 70 2e and hit enter. Type o 71 ff, hit enter and then type q. Voila! your bios password has been reset. I'm not sure if this method works properly in Windows XP though.