Even easier, download falcon 4.5 boot disk(if you have access to another computer) there are several ways to change the password, boot to mini xp and use the password changing utility there, or from the boot screen just use kon-boot and you will get right in, add another user account that is admin and log in on that one to erase your password on the other account. I work at a rental company and that is about the best utility I have found for taking care of this problem.
It seems you have not created a password reset disk while setting a password for the account. A better way to access your computer again is using password reset tool, not re-install. Ophcrack is said to be a most used free password recovery software that can solve your problem if your password length is not longer than 14 chars.