The Windows registry is a database used to store important settings and configuration information for Windows operating systems, and Windows cannot operate without it. The registry contains information and settings for all the hardware, software, users, and preferences of your computer and operating system. Whenever a user makes changes to the Control Panel settings, file associations, system policies or installed software, the changes are reflected and stored in the registry. Running an application on your computer can make several changes to your registry.

Over time, invalid entries or orphaned references can accumulate in the Windows registry. These problems may accumulate for several reasons:

• Uninstalling or incorrectly removing software, resulting in invalid file or folder references as well as orphaned startup programs

• Having missing or corrupt hardware or software drivers installed

• Deleting files referenced by shortcuts.

An accumulation of invalid entries can slow down your system, cause it to generate error messages, prevent programs from functioning properly or result in your system becoming unstable and crashing.