Find the *.pwl file in the Windows directory and delete it.
The one to want to delete will be your username*.pwl. For example, if your username is Alzheimers it would be C:\windows\alzheimers.pwl
The next time you log on it will ask you for a new password without requiring the old one. This works in Windows Millennium, but I wouldn't try it with anything made after that.
IMPORTANT Make a copy of this file and place it in your documents before you delete it. Or just move it over. That way if there are any negative repercussions, you can just put it back.
How strangely will the Tools of a Tyrant pervert the plain Meaning of Words!