Thread:Extension talk:LiquidThreads/Do I need to change the $IP to the actual path?

Do I need to change the $IP to the actual path? For example replace the $IP in require_once("$IP/extensions/LiquidThreads/LiquidThreads.php"); to require_once("c:/Mediawiki/extensions/LiquidThreads/LiquidThreads.php"); Please advice, Thanks