These are specific properties relegated to specific programs or features. Root keys are the keys that are the first node. Subkeys branch off of root keys. Every key may branch off to other subkeys or values.
Root Keys
HKEY_CLASSES_ROOT
Includes the standard class objects used by Windows. These objects can be for files like defining JPG image file.
HKEY_CLASSES_ROOT\.jpg (or HKEY_CURRENT_USER\Software\Classes\.jpg for backwards compatibility) covers user-specific associations for JPG files.
HKEY_CURRENT_USER
Stores personalized settings for current user like:
- desktop colors
- screensavers
- desktop contents
HKEY_USERS
Same information asHKEY_CURRENT_USER, but for all users
HKEY_LOCAL_MACHINE
Contains data for user-independent system configurations. Includes:
- All devices
- All programs
HKEY_CURRENT_CONFIG
If values in HKEY_LOCAL_MACHINE can have 1 or more option - such as 2 monitors, then this key defines which one is currently being used.