fwiw, I'm getting much the same problem with my ATI card; i.e. black screen, PC locks up shortly afterwards (doesn't even respond to ping, etc). From what I can tell, it seems pretty commonplace with both Nvidia and ATI, and a lot of people have observed that it's only CP77 that does this. So far nothing has fixed it.If u are on 1080TI or below (I am assuming) Drivers above Driver Version: 457.30 will make have bad influence on your rig.
After installing Driver Version: 460.79 or 460.89 (could change with newer version) my PC gets black outs. What i mean is, my PC will randomly make my both screens black or what is more weird yellow, purple, or blue, no idea how it works with the colours. At the end i have to hard reset PC, its not a good idea. It doesn't meter. You wanna save yourself time go back on driver v457.30.
I hope guys at CDPR will spread this on twitter s many are still playing on 1080 or lower gear. and latest GeForce drivers, are actually crap. In a sense, that you will go mad, really mad.