Blank screen at start, crash

When I start GD, it opens a blank (and black) window and nothing happens.
I had to crash it using task manager.

Win10 home 64bit
CPU: AMD A8-7600
Mobo: Gigabyte F2A68HM-H
GPU: PNY GeForce 8800 GT 512MB
(Mobo also has built-in Radeon R7)

I have tried repair.exe, run as admin, compatibility mode, installed latest Nvidia driver (342.01), reinstalled all things in “_CommonRedist” (run as admin), put (SteamApps\common\Grim Dawn) in my anti virus trust directory (I’m using Qihoo 360).

Odd thing: Before I had the Nvidia driver installed, GD was able to open fine but it was using built-in Radeon R7 and it was unplayable (approx 1 fps at menu, lol).

Do I have conflicting drivers (both ATI and Nvidia installed)?
Is this video card (8800 GT) no longer compatible in Windows 10?

I’m able to play other games fine such as PvZ Garden Warfare, Team Fortress 2.

Thanks for any tips/help.

After researching some more, I fixed it by adding /d3d9 in the launch option.
Deleting options.txt did not help.

Could the devs add launcher executable for /d3d9 and for /nocommit (and other launch options) with brief explanations/description?