That goes against the entire point of how XenForo's user group permission system works. Registered should be everyone's primary user group with all basic permissions. Then create advanced user groups, like one for administrators, giving them the permissions you didn't allow for Registered.
Quit doing it as you got used to in vBulletin or some of the other scripts. Those "new user groups" are meant to be cumulative - and not individualistic (although you CAN use it like that, it's not "as designed" so you have to deal with the fact of using it differently).
Brogan has a very good guide here. I'd strongly recommend reviewing it and following the way the system was designed to be used and not try to force a triangle into a round hole.