The Windows Registry stores a vast array of information about the Windows operating system, its applications, settings and configurations. This includes user-specific settings such as desktop backgrounds, window preferences and installed programs; system settings for drivers, services and startup programs; application settings for specific programs; and hardware settings for installed devices.
The Windows Registry also stores profile information, including user accounts and passwords; folder locations; environment variables; system policies; and security information and settings. It also keeps track of the most recently used programs, files, and documents and user preferences regarding the taskbar, menus, and other display elements.
In addition, types of data in the Windows Registry can include installation details for hardware and software; hardware and software vendor information; serial numbers; device drivers; DLLs and other system files; service Snapshots; and other types of Windows configuration information. Many third-party applications also store data in the Registry. All of this information is stored and organized in a hierarchical structure made up of keys, values, and data.