title: How to use xcopy to only copy files if they are newer?
body: <p>I have many web applications in a Visual Studio solution.</p>
  
  <p>All have the same post build command:</p>
  
  <pre><code>xcopy "$(TargetDir)*.dll" "D:\Project\bin" /i /d /y
  </code></pre>
  
  <p>It would be useful to avoid replacing newer files with old ones (e.g. someone could accidentally add a reference to an old version of a DLL).</p>
  
  <p>How can I use xcopy to replace old files only with <strong>newer DLL files</strong> generated by Visual Studio?</p>