Over the time, a lot of entries inside your Windows registry (in which your PC store all of system information: Windows, hardware, and software) are no longer valid and gradually becomes cluttered and fragmented.
Registry Rescue scans, removes, and repairs invalid entries, references and links in your Windows registry. Errors in your registry, and stuff left behind by other programs in your registry are one of the main causes of system slow down, computer crashes and lockups, also a potential privacy threats. By repairing errors in the registry your system's performance will be visibly increased.
Registry Rescue also performs physical defragmentation on the Windows registry file. After this process your registry will acquire linear structure which will reduce application response time and registry access time.
Download from the link : http://www.pcprivacysoftware.com/registry_rescue.html