Is this a bios password or a log on password? When you start the computer up does it load up windows and then ask for a password or does it want the password prior to starting?
You can try removing the bios battery in the computer and letting it sit for abit. This sometimes works in removing the power on password, just make sure the computer has no power flowing into the computer by the battery or power cord. If this is a log on password for windows then just reformat the harddrive and reinstall an operating system.