I had the same problem.
In my case the installer created the directories that should go to “%LOCALAPPDATA%\Topaz Labs LLC\Topaz Denoise AI” (i.e. inside your user’s local app data folder “C:\users\ YOUR USERNAME\AppData\Local”) in the Administrator users folder “C:\users\ Administrator\AppData\Local\Topaz Labs LLC\Topaz Denoise AI” instead.
Also some registry keys get created in the wrong place.
To fix this I had to
Copy the folder “C:\users\ Administrator\AppData\Local\Topaz Labs LLC\Topaz Denoise AI” with all subdirectories and their content to my own user’s %LOCALAPPDATA% folder.
Fix registry entries.
In my case the installer created the registry keys correctly for the Administrator user but not for my normal user account. Specifically the key where the path to the folder where Denoise AI finds its resources was plain empty. I had to manually enter the correct path in the registry key HKEY_CURRENT_USER\Software\Topaz Labs LLC\Topaz DeNoise AI\appMain\tgrcFolderLocation. One thing to pay attention to when doing that ist that you need to use forward slashes instead of backslashes.
Because a picture tells more than a thousand words I attach two screen shots where you can see the correct location for these keys and the values needed for the most important ones.
Keep in mind that modifying the registry can potentially damage your system. So always be sure to make a backup before using the registry editor (type “regedit” on the command line)!
This information comes with no warranty that it will work for you. But maybe some Topaz guys will eventually read it and hopefully will fix the installer so that it creates directories and registry keys in the right place from the start. No user should need to fix what they broke.