title: How to restart X Windows System for new desktop `Xfce' to take effect
body: <p>I installed Fedora 20 a while ago and now decided to install and test Xfce ui.
  I installed Desktop Switched gui utility for switching the ui.
  Now when I select xfce in the switcher utility and click apply I get the following message. </p>
  
  <blockquote>
    <p>Your desktop configuration has successfully been updated, but you must
    restart the X Window System for the changes to take effect.</p>
  </blockquote>
  
  <p>I then restart my system by doing a shutdown however my old ui (which I believe is gnome) still shows up. How do I restart the Xwindows system ? </p>