title: MS Batch: Check if drive is in use
body: <p>I need to check if a drive (Z:) is in use (e.g. in use by an application, opened).</p>
  
  <p>My Batch File looks like this:</p>
  
  <pre><code>Mount Z:
  wait 15 minutes
  check if drive Z: is in use
  
  IF NOT: unmount Z:
  ELSE: wait 15 minutes
  repeat..
  </code></pre>
  
  <p>Is there any Command for this? Thanks!</p>