Warning: require_once(vendor/autoload.php) [function.require-once]: failed to open stream: No such file or directory in E:\web\cancunta\es\php\PHPMailer\test\bootstrap.php on line 2

Fatal error: require_once() [function.require]: Failed opening required 'vendor/autoload.php' (include_path='.;C:\Program Files (x86)\PHP\v5.3\pear\pear') in E:\web\cancunta\es\php\PHPMailer\test\bootstrap.php on line 2