Description:
------------
can't execute shell command inside PHP (return unable to fork message)

Reproduce code:
---------------
<?php
echo system("C:\\WINDOWS\\system32\\cmd.exe");
?>

Expected result:
----------------
Display WIndows Version

Actual result:
--------------
Warning: system(): Unable to fork [C:\WINDOWS\system32\cmd.exe] in C:\Inetpub\wwwroot\ping.php on line 3