What you are asking about is a closed board from everyone but registered users including Spiders. Correct?
If that is the case then goto: control panel>>group management
Using the guest group line you have three options to pick from for permissions.
Forum,Site and CP.
Open each option and change all permissions to 0.
Then a guest can only access registration or login.
It takes a while to go through all the settings for each area.

Last edited by Ruben; 02/17/2009 6:58 PM.

Blue Man Group
There is no such thing as stupid questions. Just stupid answers