I got the crash problem also and in win7 and win10 alike for the last three driver versions incl beta.
Dx 11 mode crashes when im in play mode havent experecied it in normal editing.
I didnt manage to start the editor with dx12 that just gives a black screen and driver crash
but i did manage to start and running without issues yet in opengl.
But i have poor performance in opengl. i get 120 fps in roller ball demo in dx11 in editor view and in playmode but only around 50 to 70 in opengl. Is this to be expected? I havent checked the performance with a released game and i havent checked dx11 in a released ue4 game.