RegCleaner is a very popular and easy to use registry cleaning tool that is perfect for removing the leftovers of previous software installs as well as other common registry "debris". RegCleaner can detect and remove file types, entries of old software, unused DLL files, unused Shared DLLs and also allows you to uninstall and remove software from the Add/Remove list. In addition, it offers an overview of all programs that start with Windows and the option to remove selected entries. The program also provides a backup features that allows you to undo the changes , in case you run into problems. You can choose to manually select and remove entries or use the automatic cleanup feature, that will scan your system and find obsolete entries automatically. Very nice, definitely among the best of it's kind.