Create a password reset disk Windows 8 or 10

Open Control Panel
User Accounts section
User Accounts

select the link to “Create a password reset disk”
follow the instructions.

To Reset Your Password
Once you have a password reset disk, you can use it easily the next time you forget your password…
once you’ve typed the wrong password Windows 8 or 10 will show a “Reset password” link below the login box.

At this point you should have your USB already plugged in
so go ahead and hit the Reset password button, this will kick off a wizard, click next to continue
follow the instructions.