title: Visual Studio Setup Project - how to avoid duplicate entries?
body: <p>It's the first time I use Visual Studio Setup to create an installer, and there's one thing I don't understand.</p>
  
  <p>I've added the files I want via simple drag-and-drop, but the end result is that the installer creates a lot of duplicate entries, like this:</p>
  
  <p><a href="https://i.stack.imgur.com/FmPub.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FmPub.png" alt="enter image description here"></a></p>
  
  <p>in other words, for almost every one of my .dll files, Visual Studio adds a duplicate .DLL file with the same name, that cannot even be deleted. </p>
  
  <p>While the final generated installer still works correctly (because I assume one of the duplicates is overwriting the other) it has the annoying side-effect of generating a lot of warnings and also of making the final .MSI file almost twice as big as it needs to be.</p>
  
  <p>How do I avoid this?</p>