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For the forums, go to edit forums (system admin > module icon), click on the name of the forum and you will be in it's configuration section. There is a drop down box for access level and there you give permissions for who can post on that forum. You will have to edit all your forums to give access to registered users only.
Just remember that whenever you create a forum, you will need to make sure you set the access level of each one. You should have noticed that drop down box when you first started creating your forums.
