If you ever lost your Windows password, you can recover it by running a Linux utility called chntpw. You’ll need to boot into some kind of Linux Live CD to be able to run the chntpw utility. There are a number of Live CDs out there, that you can download online, to run Linux on your system, without installing it on your hard drive. The tried and true Knoppix is one option. Ubuntu and Fedora have their own versions. For the full instructions on how to recover your Windows password, check this article from opensource.com.