Hello Anselam:
I think we all know how critical the registry is. Without it, our MS O/S is dead in the water. Just creating a software like this is a huge risk because of the critical nature of the registry.
It's really sort of scary to use something like this because there is always going to be a fear that something will happen and the computer will crash.
I have been using jv16 powertools now for the last 2 - 3 years and I have never had a computer or software related crash. And it helps to speed up your computer...there is a noticeable difference in performance everytime I use it...
I certainly understand your concern, but my experience tells me that this software is really good! I highly recommend using it. You will see a performance difference for sure.
PS - You will want to compact your registry hives after running this tool, to cut down on the "holes" left behind in the registry. What I mean is, it leaves "empty spaces" in the registry, as does every registry cleaner which does not have a "compact" feature or "hive cleaner." You can get NTREGOPT from Sysinternals that will do this safely. NTREGOPT is a perfect companion tool which should be run after using the registry cleaner. You will clean up the empty spaces and improve the performance and efficiency of your computer even more.
Jim