Regshot is an open-source (LGPL) registry compare utility that allows you to quickly take a snapshot of your registry and then compare it with a second one - done after doing system changes or installing a new software product.
Wise Registry Cleaner scans the Windows registry and finds incorrect or obsolete information in the registry. This is one of many tools included in the Wise Care 365 free suite.
RegCleaner is an easy-to-use program. With RegCleaner, you can easily get rid of those old and obsolete registry entries created by software that you destroyed ages ago.
Tweaking.com - Registry Backup is a backup tool that uses the Windows Volume Shadow Copy Service to backup your system registry. From the author of Tweaking.Com - Windows Repair.