If you have a NVidia card in your computer, you probably got their control panel included to change certain 3D settings. In my system, it is located in
C:\Program Files\NVIDIA Corporation\Control Panel Client
but you may find your individual links on your desktop or in your taskbar. Anyway, once opened you go to
3D Settings > Maintain 3D Settings > Program Settings (hope I translated that right from my control panel's german version).
Click "add" and look for your lithtech.exe file (1).
I can't give you generally valid prescription what you have to do there, you just have to try and error some switches (2) - but don't forget: the file you have to work on is not nolf.exe but lithtech.exe