I think you have selected the wrong card in il2Setup before you re-started il2setup again and selected "Custom".
you have
in your [Render_OpenGL] section.
That should be HardwareShaders=1
DO NOT use the newer nV drivers they are full of bugs. check at
www.guru3d.com to find the
96.89 driverr and install that AFTER uninstalling your current driver.
Run il2setup select the nVidia 6600 and OpenGL - run the game
If you have the game running (try play a track) you're ready for step 2:
Run il2setup, select "Custom" and the options you want and your card supports.
Run the game again and see if it improved things
Once you have this working you can dive into conf.ini and change settings like water= forest= sky= etc etc etc