Direct-x problem after installing FS-X
After installation of FS-X a direct-x problem arises on start-up of Flight simulator. The program states direct-x 9 is missing in the system.
Solution
Download and install the direct-x 9.0c runtime you can find on the Microsoft website. I did not encounter this problem but found the question on a Windows 7 forum.
On another forum I found this important remark:
You do not need to install DX9.0C. DX11 is a superset of DX10.0/10.1, both of which are backwards-compatible with DX9.0C in the sense that DX9.0C software and hardware can run non-DX10/11 code. For this reason you do not install DX9.0C on Vista either, as it is “emulated” (for lack of a better word). (http://www.tomshardware.com/forum/185-63-directx-installing-directx11-problem-win7)
So on my installation FS-X did not complain about missing DX9. If anyone can give the final solution 
Can this issue be in some way related to problem concerning the video-card or driver. To be continued…