The other school of thought believes that registry cleaners are surplus to requirements options. Windows has auto-correcting features. Any overindulgence files left in the registry will be deleted later on, anyway.

And a registry cleaner can be unsafe to the system, too.

Registry cleaner tools operate under a given set of algorithm that commands them to delete files which are deemed unessential to the operations of Windows. The problem is, Windows is a "closed source" system. Only Microsoft engineers know which files are indispensable and which files are not indispensable. Developers of registry cleaners only work on experimental knowledge, and not authoritative information.

What if the registry cleaner application delete a file that it thinks is useless items, but is actually an fundamental piece of the Windows puzzle?

There is not one among the hundreds of registry cleaners that has a 100% safety guarantee when it comes to avoiding the accidental deletion of files which are essential to the operation of the system

Believe it or not, this has happened in many occasions.

Here is another argument against:

There are thousands upon thousands of potential problems for registries. Registry cleaners should possess comprehensive databases that will cover all, if not most, of these dangers.

After all, the primary purpose of the registry cleaner software is to clean the registry.

How can they clean something that they cannot find?