RegCreateKey

The RegCreateKey function creates the specified registry key. If the key already exists in the registry, the function opens it.

Note  This function is provided only for compatibility with 16-bit versions of Windows. Win32-based applications should use the RegCreateKeyEx function.

LONG RegCreateKey(
  HKEY hKey,        // handle to an open key
  LPCTSTR lpSubKey, // subkey name
  PHKEY phkResult   // buffer for key handle
);

Parameters

hKey

[in] Handle to a currently open key or one of the following predefined reserved handle values:

HKEY_CLASSES_ROOT
HKEY_CURRENT_CONFIG
HKEY_CURRENT_USER
HKEY_LOCAL_MACHINE
HKEY_USERS
Windows NT/2000: HKEY_PERFORMANCE_DATA
Windows 95/98: HKEY_DYN_DATA

The key opened or created by the RegCreateKey function is a subkey of the key identified by hKey.

lpSubKey

[in] Pointer to a null-terminated string specifying the name of a key that this function opens or creates. This key must be a subkey of the key identified by the hKey parameter.

If hKey is one of the predefined keys, lpSubKey may be NULL. In that case, the handle returned by using phkResult is the same hKey handle passed in to the function.

phkResult

[out] Pointer to a variable that receives a handle to the opened or created key. When you no longer need the returned handle, call the RegCloseKey function to close it.

Return Values

If the function succeeds, the return value is ERROR_SUCCESS.

If the function fails, the return value is a nonzero error code defined in Winerror.h. You can use the FormatMessage function with the FORMAT_MESSAGE_FROM_SYSTEM flag to get a generic description of the error.

Remarks

An application can use the RegCreateKey function to create several keys at once. For example, an application can create a subkey four levels deep at the same time as the three preceding subkeys by specifying a string of the following form for the lpSubKey parameter:

subkey1\subkey2\subkey3\subkey4

The key identified by the hKey parameter must have been opened with KEY_CREATE_SUB_KEY access (KEY_WRITE access includes KEY_CREATE_SUB_KEY access).

If the lpSubKey parameter is the address of an empty string, the function opens and then passes back the key identified by the hKey parameter.

Windows 95/98: No registry subkey or value name may exceed 255 characters.

Requirements

  Windows NT/2000: Requires Windows NT 3.1 or later.
  Windows 95/98: Requires Windows 95 or later.
  Header: Declared in Winreg.h; include Windows.h.
  Library: Use Advapi32.lib.
  Unicode: Implemented as Unicode and ANSI versions on Windows NT/2000.

See Also

Registry Overview, Registry Functions, RegCloseKey, RegCreateKeyEx, RegDeleteKey, RegOpenKey, RegOpenKeyEx, RegSetValue