title: Windows Application is installing seperate instance as opposed to updating previous version after publish
body: <p>I'm currently working on a .Net framework 4 Windows application that I've inherited from another developer(that's left my place) that updates from a UNC location.</p>
  <p>Whenever I take the old version of the app and publish the new version on top of it and run the setup it installs a separate instance of the application on the machine as opposed to updating the previous version, my suspicion is that this is due to the ClickOnce manifests being signed with a . PFX key that we have lost the password to, but I can't be sure that this is definitely the reason why.</p>
  <p>does anyone know how I'd be able to publish the app up to update the previous version without the user having to uninstall/reinstall the app?</p>