Bootcamp 6,1 Screen dark after windows boot

I have a 6,1 with dual graphics card, Intel and Nvidia 330. After loading windows on a separate partition, all displays well. No audio and etc. So I run bootcamp for the drivers and use backwards compatability as the it says it only works on windows 7 when I start bootcamp program. Starts just fine, it starts installing the graphics and then I hear sound, and the screen goes black and stays black even after a reboot. Any suggestions? Mac Catalina OS works flawlessly on other partition.