This is your basic, almost universal, ffmpeg-based video converter, though it does include older software libraries from Nvidia & AMD for GPU assisted rendering/encoding. It also adds what seems to be some ffmpeg filtering: noise removal & anti-shake. [I say seems to because there are no external code libraries for those functions.]
Using video filters was more common in the analog days to remove some of the artifacts, distortions etc. that were much more common to analog than digital video. This sort of filtering can be both iffy & complicated -- you most likely will need to adjust the filtering parameters, and there may be several, to correct whatever issue you're trying to address without introducing new problems, which is unfortunately easy. Baked-in presets, using one set of parameters for everything, are very likely to be too mild to do much of anything, out of the fear to make things worse. You're better off using video editing tools that allow you to adjust these settings, ideally letting you apply filtering only to specific segments or scenes of your video as needed. The most well known tools I'm aware of are AviSynth, VapourSynth, VirtualDub & VirtualDub2, and Handbrake. You can also of course use ffmpeg, though you may have more trouble finding documentation compared to the others listed.
That said, Vidmore Video Enhancer adds new folders for the program itself, under ProgramData, in My Documents, and in Users\ [Username]\ AppData\ Local\. I recorded about 200 new registry entries.