Web lists-archives.com

[PHP] Includes with XAMPP

I have been using Apple computers running MAMP to do my PHP web design and
never had a problem with include files, I have had to start using PC and
running XAMPP

When I am running an require_once("inc/config.php"); on the main index.php
file everything works fine, but when I go up the tree into the next folder
and use require_once("../inc/config.php"); it gives me an error. can
someone help me with this? This applies to when I am adding
include(ROOT_PATH . "inc/_dochead.php"); on any page but the main page.