Here it is, rabbit:
I know Visual Basic; I do not know beans about the Registry. Visual Studio comes with a Design Environment with which the developer creates Installer Packages, which have the extension .msi. That is the only one I have direct knowledge of, and that knowledge is limited.
I had the same problem with Free Registry Fix, but it went home, and I have not been successful in getting it back, so I decided to try CCleaner.
CCleaner identifies Registry keys as "obsolete" if they do not have values set. Right click the offending registry key in the report and select open with Regedit. Select the empty value and type in "empty". This should satisfy CCleaner so that it will no longer flag your app. {Operating assumption: the key was an orphan, which never had an assigned value and was not in use by the app. This was the case in my situation}
Some of us must learn the hard way. I tried to delete the offending keys from the installer package for my program. The big mistake: I did not remove the original installation first. Result: the uninstall procedure invoked by the installer totally crashed my system!