Microsoft Excel – MS Office 2013 can not be set as default when editing the registry

I had difficulty setting MS Office 2013 as the default instead of 2007. For my work, both have to be installed on my PC, so I can not avoid having 2007 what I hate so much on my station.

My first problem was that I could not find MS 2013 in the standard program list. Trying to search the exe file did not help either.

I followed the instructions for editing the registry in this thread:
Why does Excel 2013 not work as an "Open with …" program in Windows 7?

It seemed OK, because now MS2013 appears on the Open with.. list just like this:

Open with … List

However, when I chose the Excel 2013 icon, my Excel file will start until 2007. At this point, I have no idea what keyword to find the solution.

Thanks for the help in advance.