Free Registry Cleaners

Registry cleaners are software programs that remove unnecessary entries from the Windows Registry. Registry cleaners are especially useful for removing registry entries that point to files that no longer exist.

1.  CCleaner

CCleaner is the best free registry cleaner program I’ve tested. It’s easy to use, prompts you to backup the registry before it makes changes, and includes a number of other useful tools.
Piriform provides both installable and portable versions of their free registry cleaner.
If you’re set on using an automated tool to fix an issue you have that’s caused by a registry problem, I highly recommend you use Piriform’s CCleaner freeware registry cleaner tool.
The CCleaner registry cleaner work on Windows 8 & 8.1, 7, Vista, XP, Server 2008/2003, and older Windows versions like 2000, NT, ME and 98. 64-bit Windows versions are also supported.

2.  Wise Registry Cleaner

Wise Registry Cleaner comes in very close to the other top rated registry fix tools. They’ve put together a fantastic free registry cleaner program.
Some big pluses for Wise’s free registry cleaner include fast registry scans, scheduled scans, in place updates, and a clear separation between normal issues and those that are “unsafe,” a feature I loved. I don’t like the fact that Wise Registry Cleaner pushes for a download of Wise Disk Cleaner at the end of the installation but it’s easy to skip.
Wise Registry Cleaner comes in both installable and portable versions and can be used on Windows 8, 7, Vista, and XP. 64-bit Windows versions are supported.

3.  JetClean

JetClean, a free registry cleaner by BlueSprig, isn’t one I see mentioned a lot but I found it to be very well done.
JetClean scanned the entire registry in just a few seconds and has a well designed interface.

There are two major things I didn’t like about JetClean. One: The number of cookies that JetClean considers keepable, by default, is a bit excessive. Two: It tries to install a toolbar, but you can decline it during installation. I also don’t like that there’s not an easily available portable version of JetClean. Yes, one exists, but you have to “generate” one from within the installed version of JetClean on your computer. Strange!
The JetClean registry cleaner supports both 32-bit and 64-bit versions of Windows 8, Windows 7, Windows Vista, Windows XP, and Windows 2000.