Help setting 6600gt for fs9

As newbee to decent grfx, I find the defaults on fs9 display is the best I can achieve.
Any of the settings I alter make things worst.
Cloud settings, base and tops come way out.
How do you get crisp clear sky above cumulus tops, with unlimited viz only ?.
When draging with mouse the FSNav window, over the windscreen, it leaves
Any of the settings I alter make things worst.
Cloud settings, base and tops come way out.
How do you get crisp clear sky above cumulus tops, with unlimited viz only ?.
When draging with mouse the FSNav window, over the windscreen, it leaves