Reinstalling TCC-RT 21.01.57 triggers a new install instead of update/reinstall

Aug 23, 2010
I've been rolling updates of my systems, and had to install TCC-RT twice on a desktop, since first install partially failed due to a trick I had to play with localization DLL's.
The first time I installed it, the upgrade fired nicely, correctly discovered the installation path of a previous version and proceed to upgrade. The process finished successfully except I had to skip language DLL's.
Removing localization DLL's symlinks and trying to reinstall the program, it did not see the existing installation and offered a new install into default path.