When trying to migrate from Windows 7 to 8.1 I learned that I would lose my installed applications. This was especially frustrating because I knew from the upgrade assistant that there is an option to keep them – it is just not available for my configuration. And even the official guide states that I would have to reinstall all apps.

The solution was: First migrate to Windows 8 (the option to keep your apps is available here) and then to 8.1 (which again allows you to keep your apps). My system is up and running and I did not have to reinstall anything. Voilà! The only question which remains is: why?