title: Windows PowerShell to find duplicate lines in a file
body: <p>I need to find the duplicate values in a text file using power shell
  let's say if the file content is </p>
  
  <pre><code>Apple
  Orange
  Banana
  Orange
  Orange
  </code></pre>
  
  <p>Desired output should be</p>
  
  <pre><code>Orange
  Orange
  </code></pre>