Windows Registry hives

Name Short name Description
HKEY_CLASSES_ROOT HKCR Used by Windows 3.1, 9x/Me and NT 4 and later
Refers to values in both HKEY_CURRENT_USER\Software\Classes and HKEY_LOCAL_MACHINE\Software\Classes
HKEY_CURRENT_CONFIG HKCC Used by Windows 9x/Me and NT 4 and later
Refers to the current control set in HKLM
HKEY_CURRENT_USER HKCU Information regarding the current active user
Used by Windows 9x/Me and NT 4 and later
Refers to the active user key in HKEY_USERS
HKEY_DYN_DATA Dynamic data
Used by Windows 9x/Me
HKEY_LOCAL_MACHINE HKLM Local settings
Used by Windows 9x/Me and NT 4 and later
HKEY_PERFORMANCE_DATA Performance data
Used by Windows NT 4 and later
HKEY_USERS HKU Information about all active users
Used by Windows 9x/Me and NT 4 and later