xampp localhost error

Warning: require(C:\xampp\htdocs\app\config.php): failed to open stream: No such file or directory in C:\xampp\htdocs\app\boot.php on line 22

Warning: require(C:\xampp\htdocs\app\config.php): failed to open stream: No such file or directory in C:\xampp\htdocs\app\boot.php on line 22

Fatal error: require(): Failed opening required 'C:\xampp\htdocs\app\config.php' (include_path='.;C:\xampp\php\PEAR') in C:\xampp\htdocs\app\boot.php on line 22

<?php

define( "ROOT_PATH", realpath( dirname( dirname( __FILE__ ) ) ).DIRECTORY_SEPARATOR ); 
define( "APP_PATH", ROOT_PATH."app".DIRECTORY_SEPARATOR ); 
define( "LIB_PATH", ROOT_PATH."lib".DIRECTORY_SEPARATOR ); 
define( "MODEL_PATH", APP_PATH."model".DIRECTORY_SEPARATOR ); 
define( "VIEW_PATH", APP_PATH."view".DIRECTORY_SEPARATOR );   [USER=1333350597]Set[/USER]_magic_quotes_runtime( FALSE ); 
if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) && substr_count( $_SERVER['HTTP_ACCEPT_ENCODING'], "gzip" ) ) 
{ 
    ob_implicit_flush( 0 ); 
    if ( @ob_start( array( "ob_gzhandler", 9 ) ) ) 
    { 
        header( "Content-Encoding: gzip" ); 
    } 
} 
header( "Date: ".gmdate( "D, d M Y H:i:s" )." GMT" ); 
header( "Last-Modified: ".gmdate( "D, d M Y H:i:s" )." GMT" ); 
if (isset($_GET["showerr"]))
	error_reporting (E_ALL);
require LIB_PATH.'incube.php';
require( APP_PATH."config.php" ); 
require( LIB_PATH."webservice.php" ); 
require( LIB_PATH."widget.php" ); 
require( LIB_PATH."webhelper.php" ); 
require( APP_PATH."metadata.php" ); 
require( MODEL_PATH."base.php" ); 
require( APP_PATH."components.php" ); 
require( APP_PATH."mywidgets.php" ); 
$cookie = ClientData::getinstance( ); 
$AppConfig["system"]["lang"] = "en";//$cookie->uiLang; 
define( "LANG_PATH", APP_PATH."lang".DIRECTORY_SEPARATOR.$AppConfig["system"]["lang"].DIRECTORY_SEPARATOR ); 
define( "LANG_UI_PATH", LANG_PATH."ui".DIRECTORY_SEPARATOR ); 
require( LANG_PATH."lang.php" ); 
$tempdata = explode( " ", microtime( ) ); 
$data1 = $tempdata[0]; 
$data2 = $tempdata[1]; 
$__scriptStart = ( double )$data1 + ( double )$data2;
?>