Uninstall / Disable Norton Family

A former employee installed Norton Family on a standalone work computer running Windows XP..  He is no longer with the company and I am now getting messges saying, "You have reached your time limit.  To extend your time limit, ask your parents.....".  How do I Uninstall or Disable this Norton Family?   I am not able to contact the former employee.  I need to be able to use that computer and I cannot.  Please tell me what to do.  Thank you.