System Recovery Options

Hello, what do you do when you get to the system recovery options and the administrator account has been disabled. And the only open account the person can't remember the password. How would I go about doing a factory rest. I tried the pressing the 0 key at start up not working. I used F8 and got to the system recovery options but can't get past the To access recovery options, log on as a local user?
~ROB~Thanks for any help