The routine use of Windows registry cleaners isn't needed and is dangerous. Leave the registry alone and don't use any registry cleaner. Despite what many people think, and what vendors of registry cleaning software try to convince you of, having unused registry entries doesn't really hurt your system.
The question is, of course: Did these invalid entries affect your PC's performance in any way or were they just junk lying about?
Did you measure your PC's performance before and after? Registry cleaners give the user a warm and glowing feeling inside but nothing else. So far nobody has come up with any solid evidence to the contrary.
Orphaned entries exist, certainly. No one has ever denied that. Just as no one has ever proved that those orphaned entries cause any harm. The risk of a serious problem caused by a registry cleaner erroneously removing an important entry is far greater than any potential benefit it may have.
"Granted", most registry cleaners won't cause problems each and every time they're used, but the potential for harm is always there.
The registry contains all of the operating system's "knowledge" of the computer's hardware devices, installed software, the location of the device drivers, and the computer's configuration. A misstep in the registry can have severe consequences. One should not even turning loose a poorly understood automated "cleaner," unless he is fully confident that he knows exactly what is going to happen as a result of each and every change.
Having seen the results of inexperienced people using automated registry "cleaners," I can only advise all but the most experienced computer technicians (and/or hobbyists) to avoid them all.
A good registry scanning tool, in the hands of an experienced and knowledgeable technician or hobbyist can be a useful time-saving diagnostic tool, as long as it's not allowed to make any changes automatically. But I really don't think that there are any registry cleaners that are truly safe for the general public to use: such tools simply are not safe in the hands of the inexperienced user.
