The registry is organized around six major keys.
|HKEY_CLASSES_ROOT||This key holds file associations and OLE (Object Linking and Embedding) data.|
|HKEY_USERS||This key holds user preferences, including desktop set-up and network connections.|
|HKEY_CURRENT_USER||On a PC with only a single user, this key is a duplicate of the HKEY_USERS key. On a PC with multiple user log-ins, this key contains the preferences of the currently logged-in user.|
|HKEY_LOCAL_MACHINE||This key manages the hardware and software that is installed on the PC.|
|HKEY_CURRENT_CONFIG||In addition to duplicating the HKEY_LOCAL_MACHINE key when running, this key also contains any configuration changes that were made in the current session and holds information on the printers and fonts that are installed.|
|HKEY_DYN_DATA||This key records system performance information and keeps information on Plug and Play devices.|
The above keys are the highest level of organisation in the Windows directory and are referred to by Microsoft as Hives.