It might be a challenge to recover. Did you build the Windows Embedded image? If so do you have the build files in which the password was set?
Nirsoft might have a password recovery utility that might help: http://www.nirsoft.net/utils/index.html#password_utils
Here is one other option: https://www.howtogeek.com/96630/how-to-reset-your-forgotten-Windows-password-the-easy-way/