To clarify: once you start ATVO and you're still on the old launcher you should receive a notifcation that it needs to be updated. In order to be able to update you might need to uninstall the old ATVO launcher using the Windows uninstall dialog.
Please let us know if you have any trouble doing it. If you do not receive the notification and ATVO does not run please manually uninstall the old ATVO launcher and grab the new version (2.1.0.0) from our download page:
https://atvo.appgineering.com/Download