PHP - 在System32中找不到某些文件夹

During two hours, I've tried to find an issue for my problem. I have a script which sorts folders of System32 :

$iterator = new DirectoryIterator($_SERVER["SystemRoot"] ."\System32");
foreach ($iterator as $fileinfo) {
    if ($fileinfo->isDir())
        echo $fileinfo->getFilename() . "<br />";
}

But when I check result, I see that some folders are missing.

Someone has an idea to solve it ? Thanks a lot.

Edit : When I create a new folder, it's not find too.

Edit' : I work on a Windows Server 2012 R2 (IIS 8.5).