CCleaner does have a limited registry cleaner in that sense. I use it here often enough as well as having tried various other programs. What is seen mostly there however is a cleanup of log files, memory dumps, temp folders. and other clutter that slows drive access time down.
But for an effecttive tool that will run on Vista as well as 95 plus display anything you have installed even without knowing like adwares the "new" entries will show up in the main window seen in the image below.
Once you clean up a drive things seem to run faster. That's another thing that people often don't realize when copy, creating, deleting, and then even downloading, moving more files, and repeated deletion as well as creation along with storing them. clutter and fragmented files will remain regardless of what tool is used there.