Security on Registry

[Steve]

If an admin deletes all of the permissions on a registry
key, is there any way to remove that key or readd new
permissions?

 

[Roger Abell]

Sure. The ACLing rules for the registry are the same as
for NTFS. The Owner can always set permissions, even
in the absence of any permissions being granted, and the
admin accounts can take ownership in order to be able
to grant permissions.
Once some account has a grant allowing delete then the
key/value may be deleted.