Newbie messed up... How do you restore Uses Groups?

[93Corvette]

I'm a newbie, and I am trying to set up all of my permissions.
Rather than printing off all the settings in the "Default User Groups" so I know where they were to begin with, I went ahead and made the "Unregistered Users" to "No". Now the unregistered users cannot see anything when they type in the www address, only that they need to register.
I want it back to the way it was where they can see but not post. (for now)..... So how do I restore my settings back to the way it was orginally delivered? (In layman's terms)
Thanks in advance....