If you have a Windows operating system and you find yourself locked out, Linux is there for the rescue with a very handy tool, ntpasswd.
ntpasswd can be described as an “Offline NT Password & Registry Editor” and it’s a tool that can be used to reset the password of any user that has a valid account on a Windows system.
Full article here:
How to Reset the Password on Any Windows Version, Including 8.1, From Linux (Softpedia)
Resetting Windows administrator password using Linux (Techie News)