How to reset my password

I am the only adminisster and just reset my password it wont let me back in didnt right it down and didnt create a reset password key how can i get onto my computer

If you've forgotten your Windows password and you're on a domain, you should contact your system administrator to reset your password. If you're not on a domain, you can reset your password by using a password reset disk or by using an administrator account.

If you forget the administrator password and don't have a password reset disk or another administrator account, you won't be able to reset the password. If there are no other user accounts on the computer, you won't be able to log on to Windows and will need to re-install Windows.