Hi Guys, I might get a few people who disagree with me on this one, but Registry defrager's and cleaners really don't do much if anything for performance overall (ducking now) !!! Not that they are necessarly a bad idea, but if you are looking for performance improvement cleaning the registry will do next to nothing. You are far better off making sure your drive is well defraged, and all the unnecessary bloatware is unloaded - Acrility is excellent for that. Don't get me wrong I use CCleaner frequently, mostly to clean up the crap - Temp files, cookies, etc, and I do scan the registry regularly, but I have never found any performance improvement after cleaning out the registry, it does however help prevent (and sometimes solve) registry problems.
I am not in anyway saying there is anything wrong with CCleaner or any other reg utility, I am just pointing out there is lots of hype about big performace improvements made by some of these tools and in my experience (and numerous technical articles I subscribe to) there is little performance gain.
If you want the max performance from your system it is always wise to stick to the basics, clean up the junk, defrag drive(s), and keep running processes to what you need to operate your favorite Sim - FSX of course.