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

Optional 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) 
HKEY_DYN_DATA (0x80000006) 
Note that HKEY_DYN_DATA is a valid tree for Windows 95 and Windows 98 computers only.