TexStudio does not find MIKTex LaTeX installation, AutoConfig does not work

I installed MIKTeX 2.9.5105 64 Bit on my Windows 8.1 64 Bit OS. Then I installed TeXStudio 2.7.0 as my favourite TeX Editor.
Starting up TeXStudio, it did not find my MIKTeX Installation and therefore refused to compile documents.

How-I-fixed-it:

I found some hints here:
http://tex.stackexchange.com/questions/71073/i-installed-texstudio-and-miktex-in-the-wrong-order-how-can-i-do-a-clean-instal

Close TeXStudio. In Windows Explorer navigate to: %APPDATA%\texstudio\ (Alternatively you can navigate to C:\Users\YOUR_WINDOWS_ACCOUNT_NAME\AppData\Roaming\texstudio).

Delete texstudio.ini file.

Restart TeXStudio.

This fixed it for me.