I know it gets a lot of flack for having to be run multiple times (to fully clean the registry), but it always does the job, and never have I seen CCleaner render a system unbootable or worse for wear. Here are a few apps you can trust to handle the job and keep your registry as clean as possible (without manually running a fine comb through every entry). There are tons of registry cleaners out there, some of which do what they promise. Aside from being fastidious with your software management, you can use various tools to help keep the registry clean and free from errors. And when the registry gets mucked up, bad things happen. With rampant and careless software installation, the registry gets mucked up quickly.

So it behooves the admin (or the user) to keep the registry as clear of errors as possible. From within that hierarchical database, the operating system can be rendered unbootable, slow, or problematic.

Along with viruses and malware, the registry is the Achilles Heel of Windows.

Reg cleaner for mac