CCleaner, Wise Registry Cleaner and Jetclean are all highly rated freeware registry cleaners. CCleaner is rated as spectacular by the editors of CNET and received four out of five stars from CNET users.
CCleaner is reported as being very simple to use when backing up registry files and scanning the registry for issues. It is compatible with most versions of the Windows operating system, including older versions such as XP and Windows 2000, as well as being suitable to use with Mac OS X versions 10.6 to 10.11. The program is available in both an installable version and a portable version that can be run without installing any files.
Wise Registry Cleaner is another highly rated registry cleaner. The program's reporting system makes it a great option for users who lack experience cleaning the computer registry, as the software differentiates between "normal" registry issues and those that are dangerous and need to be fixed urgently. Like CCleaner, Wise Registry Cleaner is available in both installable and portable formats. It received four out of five stars from both editors and users of CNET.
JetClean is an extremely fast registry cleaner, which reviewers say scanned their entire registry in only a few seconds. It offers the option of scheduling registry scans, as well as automatically backing up the registry. JetClean scored four out of five stars from the editors at CNET as well as the users, but many reviewers stated that the program installs malware during installation and advised caution while using this program.