The game selects only integrated graphics(sD3DDevice="Intel® HD Graphics Family") not GT 740m.

If I force to 740m in Fallout4Prefs.ini, it still work on intel HD.

Also, I cannt change the resolution and set fullscreen from launcher(from Fallout4Prefs.ini it works).

P.S. Win8 64, latest drivers, in geforce experience set nvidia adapter for fallout4 and fallout4launcher aplications.

A known issue. For now you have to make sure your monitor is plugged in to the GPU monitor port and not the motherboard one.