Thanks for the reply
I reinstalled the latest drivers, in custom/clean method, but unfortunatly it did not fix my issue.
But looking deeper into it, my problème isn't exactly the same as the one I initially posted.
Currently, i DO have the sliders options in the TAB menu, so I'm guessing things related to hlsl are running.
(that wasn't the case at my initial post some months ago)
What is missing is the squarrish effect (hq4x ?)
If I change that I choose instead "scanlines" something, than the scanlines are correctly displyed (in the properties/advnced tab)
But why does hq4x doesn't have any affect anymore ??