In CMD (Command Prompt) type net user and it will bring up all the user accounts.
Step 3: What to do next.
Once you find the account that you want type net user then account name then space *
Step 4: Then you are almost done.
then hit enter and it will say enter new password. Do that hit enter and enter the desired password again. hit enter and the password is saved. You can also start you windows PC with CMD and do this. You can also do this on a guest account.