Hello,
I am afraid but I have not heard about this before. Correct me if I am wrong: for the live site you want to use Windows authentication and for the administration interface Forms authentication?
This does not make much sense.
Anyway, you can set the
secured web site area for the root document - so, entire web will be secured and if somebody browses to the web, the visitor is redirected to logon page at first. then, if the user account is granted with pemrissions for administration interface, she can enter it. Otherwise, access is denied, user has to log out and log in using appropriate credentials.
Best regards,
Juraj Ondrus