Registry keys with weird permission settings

>I have a whole hierarchy of registry keys I need to delete.
>
> When I click on the top-level key I get: Access is Denied.
>
> Right click then gives the interesting message: You do not have permission
> to view the current permission settings for xxx, but you can make
> permission changes.
>
> I then go into Advanced / Owner, take ownership, and give myself full
> control.
>
> When I try to delete the key, I get the message: Error while deleting key.
> Some child keys then show up, all with the same write-only permission
> setting. These child keys extend for some depth and width.
>
> If I try to replace all existing inheritable permissions from the
> top-level key on the children, I get: Registry Editor could not set
> security in the key currently selected, or some of its subkeys.
>
> I don't have the patience to plod all the way through the hierarchy, and
> I'm too far into RC2 to want to go back and re-install.
>
> Anyone got any ideas on how to get rid of these guys?