title: php exec: does not return output
body: <p>I have this problem: 
  On a ISS web server, windows 7 x64 professional, zend server installed. Running this command under php:</p>
  
  <pre><code>exec('dir',$output, $err);
  </code></pre>
  
  <p><code>$output is empty, $err=1.</code> So exec is not returing the output, it seems has some errors.
  Php <code>disable_functions</code> is empty, php is not on safe mode, is standard, I check all option.
  It seems to be a general errors, even search on google do not give results.</p>
  
  <p>Please write every one his experince and eventual solutions or workarounds.</p>