Thanks for the answer.
Yes I have read all that and made several re-installs already with no positive result.
I used the 707 (and 727) for a long time under Vista and Windows7.
As I am more an occasional simmer I never took the time to switch to P3D (I also didn't want to have pay again for the planes I had already).

What I would like to know is if there is anybody who has the CS707 working correctly  in FSX under Windows 10 ?
Thanks in advance.