Warning: require_once(XML/RPC/Server.php) [function.require-once]: failed to open stream: No such file or directory in C:\ms4w\apps\chameleon\htdocs\common\installer\server\server.inc.php on line 2

Fatal error: require_once() [function.require]: Failed opening required 'XML/RPC/Server.php' (include_path='.;\ms4w\Apache\php\PEAR') in C:\ms4w\apps\chameleon\htdocs\common\installer\server\server.inc.php on line 2