okay ! i've downloaded fallout 4 and is excited like anyone of you, but when the game start up it crash !!
my computer spec is:

i7-4720 2.6Ghz

8Gb ram

Nvidia GTX960..

And what i do is go the >Documents\My Games\Fallout4
and inside the fallout 4 file there is a file call as Fallout4Prefs.ini
what you gonna do is open it and under the display section you are going to find these thing :

change the data that shown as above

and you are ready to play in full screen

but remember you can only get this effect from directly opening the game file which is>>>Fallout4.exe

And do not open the game from the Launcher because you couldn't get the full screen from there

this is only my way for making the fallout 4 go "full screen"
you guys can try it if you think it's going to work
but i don't take any responsible for screwing up your game or computer
thanks and have a nice day !! game on !!!