title: How to implement WiX installer upgrade?
body: <p>At work we use <a href="http://en.wikipedia.org/wiki/WiX" rel="noreferrer">WiX</a> for building installation packages. We want that installation of product X would result in uninstall of the previous version of that product on that machine.</p>
  
  <p>I've read on several places on the Internet about a major upgrade but couldn't get it to work.
  Can anyone please specify the exact steps that I need to take to add uninstall previous version feature to WiX?</p>