i know very little about the "registry". are you saying that the type of "registry errors" found by the scan are harmless, and do nothing to slow down the system as the program claims.
"clean and defragment your registry" for a faster computer is what the add says. cleans up "system errors", "user errors" "third party errors".
If you really feel the need use CCleaner ( Free ). I have used it for years and it only deletes the Safe items and I have never seen any issues with bad edits.