title: Why do I have two users with uid 0 on my Mac?
body: <p>When I execute following code in terminal:</p>
  <pre><code>dscl . -list /Users UniqueID
  </code></pre>
  <p>The output shows two users with <strong>uid 0</strong>: one named <strong>root</strong>, the other named <strong>newuser</strong>.</p>
  <p>But when I execute:</p>
  <pre><code>cat /etc/passwd
  </code></pre>
  <p>There is only one user with <strong>uid 0</strong>, i.e. root.</p>
  <p>I want to know why the answers of above commands are different, and how I can delete the newuser.</p>
  <p>I am using the newest version of Mac OS X.</p>
  <p>I found this question when I failed to install parallels desktop trial edition. The error message is:</p>
  <blockquote>
  <ol start="15476">
  <li>Cannot install Parallels Desktop because there is a non-root user account with the UID 0 in your system (<a href="http://kb.parallels.com/cn/122763" rel="nofollow noreferrer">http://kb.parallels.com/cn/122763</a>)</li>
  </ol>
  </blockquote>
  <p>I've already called apple support for help, but they had no solution.</p>
  <p>Update:</p>
  <p><a href="https://i.stack.imgur.com/LJENb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/LJENb.png" alt="it se" /></a>
  <a href="https://i.stack.imgur.com/aPscr.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/aPscr.png" alt="![enter image description here" /></a></p>
  <p>It seems that <strong>newuser</strong> runs the processes which root should run. Furthermore, the <code>ps</code> command is also run by newuser, but my user name is <strong>xlnwel</strong></p>
  <p>What on earth is this <strong>newuser</strong>?</p>
  <p>Update 2:</p>
  <p><a href="https://i.stack.imgur.com/Y6YmC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Y6YmC.png" alt="enter image description here" /></a></p>
  <p>I have no idea what I have done yesterday (maybe just reboot the computer), but today these processes are run by <strong>root</strong>. but there are still two users with 0 when I run:</p>
  <p><code>dscl . -list /Users UniqueID</code></p>