Reset Topaz DeNoise to default settings

My Topaz DeNoise has been working to perfection, then I changed to ouput to DNG and the image came back darker than the original. Then I went back and reset to TIF and the ouput is still coming out darker than the original. Is there a way to reset the preferences to default, or should I remove the program and reinstall?

Did anyone bother to answer this?

Still no answer…