It depends on which password it is (Windows, hard disk, PC hardware) the PC Hardware ones are designed to turn stolen PCs into scrap. In any case I don't think that people should post how to on open forums as it only encourages the theft of notebook computers - so I won't.
However if you take it o a local computer shop with ID and proof of ownership i am sure that they will be able to help you if they can.
t, April 2008