[peterska2]

Usergroups > Add New Usergroup > Select Registered Users in the top dropdown and click GO

Rename the usergroup to something like Registered Users - Approved and click save.

(Doing it this way makes it inherit all the permissions so you don't have to set them all up again)

Then rename your registered users usergroup to Registered Users - Not Approved and change Follow Forum Moderation Rules to NO by going to

Usergroups > Usergroup Manager > Registered Users > Edit

Finally create a promotion to move users from one user group to the other by going to

Usergroups > Promotions > Add New Promotion

Set the top usergroup list to Registered Users - Not Approved
Enter 1 in the posts box
Set Promotion Strategy to Posts
Set Promotion Type to Primary Usergroup
Set the bottom usergroup to Registered Users - Approved

Click Save

Finally, to move all users with more than one post already into the new usergroup without waiting for the scheduled task to run, do this

Scheduled Tasks > Scheduled Task Manager > User Promotions > Run Now