Uninstalling software which is out of date or no longer needed is often times a straightforward and easy process — at other times it can create problems. In particular, if the application does not uninstall properly — or if it does not have an un-installer module — can result in unnecessary entries being left in your registry. Over time, these unnecessary registry entries can cause your operating system to function inefficiently — and you may even experience an increase in system crashes. But with a registry cleaner, these hassles are largely eliminated, as the software will automatically scan your registry entries and remove those which are no longer needed.