During the normal course of operations of a Windows PC, the Registry is constantly queried, manipulated, and altered by the OS itself and the applications installed and ran by the human user.

The Registry is a centralized resource of the Windows OS. The sub-Key HKLMSOFTWARE is the common section of the registry where user-installed applications will store their proprietary settings and configuration information, including the information required for licensing and un-installation of the application. For example, the subsection HKEY_LOCAL_MACHINE (HKLM) contains all the Keys pertaining to the local machine-specific configuration data and the subsection HKEY_CURRENT_USER contains all the Keys pertaining to the user-specific configuration data.

The registry is split into “hives”, subsections of logically grouped Keys, pertaining to various aspects of the hardware and OS environment. Multiple Values can be stored under one Key, with the condition that each Value has a unique name and the value (of the name/value pair) has a predefined type selected from one of the standard registry value types. Keys are similar to folders, and can be nested within other Keys. The Registry’s elementary components are Keys and Values. The Windows OS provides an API for the orderly access to the Registry. Implemented as a database, it provides database-like features such as atomic updates, strong data typing and versioning and backup/restore services. The Registry provides features that enhance the OS security and stability. In addition to setting for high level user-installed applications and programs, the Registry contains settings for low level components and devices of the Windows Operating System (OS). The registry was introduced with Windows 3.1 and Windows NT, replacing the less advanced mechanism of INI files. The Registry is a centralized, hierarchical database that stores all application settings in standardized form.

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