Warning: require_once(x.php) [function.require-once]: failed to open stream: No such file or directory in E:\phpstudy\WWW\index.php on line 12

Fatal error: require_once() [function.require]: Failed opening required 'x.php' (include_path='.;C:\php\pear') in E:\phpstudy\WWW\index.php on line 12