PHP WMI get hostname

<?php

$pc = "127.0.0.1"; //IP of the PC to manage

$WbemLocator = new COM("WbemScripting.SWbemLocator");
$WbemServices = $WbemLocator->ConnectServer($pc, 'root\\CIMV2', '', '');
$WbemServices->Security_->ImpersonationLevel = 3;

$disks = $WbemServices->ExecQuery("SELECT Name FROM Win32_ComputerSystem");

foreach ($disks as $d) {
    print( $d->Name);
}