title: How Can I Get My File Association to Open Multiple Files in a Single Program Instance?
body: <p>I have set up a file extension in the Registry for my program <a href="http://msdn.microsoft.com/en-us/library/bb776883.aspx" rel="noreferrer">as Windows requires</a>. </p>
  
  <p>In the Registry, under shell/open/command, I've got:</p>
  
  <pre><code>"C:\MyProgramPath\MyProgram.exe" "%1" 
  </code></pre>
  
  <p>This works fine for me. When someone clicks on one or more files associated with my application, my application correctly opens the file(s) but each one is opened in a separate program instance.</p>
  
  <p>Is there any way I can do this and open up all files in one program instance?</p>