Parameter that specifies the tree that contains the sSubKeyName path. The default value is HKEY_LOCAL_MACHINE (0x80000002). ...

Parameter that specifies the tree that contains the sSubKeyName path. The default value is HKEY_LOCAL_MACHINE (0x80000002). The following trees are defined in Winreg.h: 
HKEY_CLASSES_ROOT (0x80000000) 
HKEY_CURRENT_USER (0x80000001) 
HKEY_LOCAL_MACHINE (0x80000002) 
HKEY_USERS (0x80000003) 
HKEY_CURRENT_CONFIG (0x80000005)