Definindo SITE_ROOT

Bom dia to definindo o site_root aqui, mas um arquivo não esta indo.

//initialize.php
<?php

// Define the core paths
// Define them as absolute paths to make sure that require_once works as expected

// DIRECTORY_SEPARATOR is a PHP pre-defined constant
// (\ for Windows, / for Unix)
defined('DS') ? null : define('DS', DIRECTORY_SEPARATOR);

defined('SITE_ROOT') ? null :

define('SITE_ROOT', DS.'xamp'.DS.'xampp'.DS.'htdocs'.DS.'photogallery');

defined('LIB_PATH') ? null : define('LIB_PATH', SITE_ROOT.DS.'includes');

// load config file first
require_once(LIB_PATH.DS.'config.php');

// load basic functions next so that everything after can use them
require_once(LIB_PATH.DS.'functions.php');

// load core objects

require_once(LIB_PATH.DS.'session.php');
require_once(LIB_PATH.DS.'database.php');

// load database-related classes

require_once(LIB_PATH.DS.'user.php');

?>

O config.php , não está indo, dentro da classe dataBase eu coloquei o require pro config assim:

require_once(LIB_PATH.DS."config.php");

Porém da erro:

Warning: require_once(LIB_PATHDSconfig.php) [function.require-once]: failed to open stream: No such file or directory in C:\xamp\xampp\htdocs\photogallery\includes\database.php on line 2

Fatal error: require_once() [function.require]: Failed opening required 'LIB_PATHDSconfig.php' (include_path='.;C:\xamp\xampp\php\PEAR') in C:\xamp\xampp\htdocs\photogallery\includes\database.php on line 2

Abs