title: Add menu item to Windows context menu only for specific filetype
body: <p>I've developed an application that load an image using the context menu of window (right click on the file) and for the moment is working, but the reg key is on</p>
  <pre><code>HKEY_CLASSES_ROOT\*
  </code></pre>
  <p>and it works with all files.</p>
  <p>I want that the menu item on the context menu should be displayed only with .jpg files.</p>
  <p>How can I do that? Which registry keys should I use?</p>