To cg, passwords are NEVER EVER stored in a volatile way. Unplugging, and even removing the support battry for a few day will never erase any hardware password.
As OS and profile passwords are stored on disk along with system files, cutting off the power can't have any effect. Otherwize, it would also whipe out the OS, all applications and all saved files.
As T said, it would be unethical to post a "how to reset password" method on any public place. Even on a private forum, it would be very dubious.
Electro, September 2011