Thanks - yes, it's the stock GeForce GTX 1050 Ti. GeForce's utility says my drivers are up to date.
At first, I just swapped the drive without changing anything, but when that didn't work, I uninstalled BG3 and Steam, deleted my Larian folders, and reinstalled everything.
I tried installing Skyrim from Steam and you're right, that crashes too, shortly after I try to start a new game.
I'll try the old drive soon.
