Change your slash to backslash.
defined("DS") ? null : define("DS", DIRECTORY_SEPARATOR);
defined("SITE_ROOT") ? null : define("SITE_ROOT", "C:".DS."wamp".DS."www".DS."your_website");
$file_name=$_FILES['file']['name'];
$file_tmp=$_FILES['file']['tmp_name'];
$file_upload_to=SITE_ROOT . DS . "Perf_Masc";
move_uploaded_files($file_tmp, $file_upload_to . DS . $file_name);
, php , echo __DIR__ PHP 5.3 , echo dirname(__FILE__).