Rick, I originally searched the registry for "Paint Net" and was amazed to find so many Keys, etc, that were referenced.
I thought that I had deleted all of them but Paint Net would still not load, so I went through the routine again and found additional references that had to be deleted.
I guess that I shouldn't have called them "Hidden" but just items that weren't obvious. Either I missed them on the first pass or it took a couple of passes to ferret them all out.
Once that I really got the registry clean, all was well. (I had tried cleaning the registry using the CClean program but that apparently was not aggressive enough).
Walt999