Question: After I clean my registry using Registry Power Cleaner, why do a few critical errors still show up when I run the scanner again?
Answer: Some registry entries cannot be deleted, either because they are recreated immediately after they are deleted or because they are blocked from deletion. These registry entries will not cause any problems for your system. If you prefer not to see such entries, click "show details," then click the checkbox next to the entry until it becomes an "i". The registry entry will be ignored in future scans.
Sometimes programs abuse the registry or don’t use the registry as designated, much like you might decide to write your passwords in an address book. Somebody examining the address book will point at those entries and say, "these are not addresses," but you probably will not allow them to remove them from your address book.