I downloaded the trial version of reg vac for my Vista system. I see no performance improvement. I have run it frequently.

  RegVac is a registry cleaner.  This means that it cleans the registry.
  RegVac cleans out trash entries, bad entries, and entries that can cause problems.  Sometimes this improves the performance, sometimes it doesn't.  Even when it does improve the performance, the improvement may not be enough for you to notice.  Whether there is an improvement in performance or not, still RegVac is keeping Windows clean which can avoid both current problems and future problems.

What Ray says is true. I do lots of downloading, copying & pasting, creating & deleting folders and lots of moving things from one of my 6 drives to another. I can really see an increase in speed and performance where you might not but believe me, it IS happening. The same with defragging your hard drives. Many people say that it doesn't make a differance but I can see it on my computer.

onemaddude