In REGEDT32 you can take OWNERSHIP and diddle with the RIGHTS of registry keys. You should be Administrator for this to work.
In short, if one sets a key to readonly, it would be proper to deny REGEDIT even from the Administrator.
While attempting to delete McAfee from my register, several entries said, "not authorized to edit or delete this file". There is not anything wrong with the program. However, I have been using Norton Utilities for many years. You can not run both. McAfee was pre-installed on this computer when I purchased it. Is there any way to eliminate these "Update" files so that I do not get all of the files all back each time I am on the internet? In checking with McAfee they only gave inromation to go to "Add/Rmove Programs" in Control Panel.