Entries in this key describe the physical state of the computer, including data about the bus type, system memory, and installed hardware and software. HKEY_LOCAL_MACHINE contains subkeys that hold current configuration data, including Plug and Play information (the Enum branch, which includes a complete list of all hardware that has ever been on the system), network logon preferences, network security information, software-related information (such as server names and the location of the server), and other system information.