I have no idea where to look for this, all I know is I'm using DirectX 11.
I think it should be in your nVidia control panel (either in the system Control Panel, or as an icon on your quicklaunch bar.) You'll have to navigate the windows yourself to get the driver--I don't have nVidia products. Probably under "About" or similar heading. I'm not sure if I'm able to support driver information in the backend anyways, after further research.
From your other replies, it's clear the initialization routine is not working right. I don't quite understand what could be failing though, because the window is resized while it's hidden before it's shown for the first time, and you mentioned that resizing fixes the problem.
If you would be interested, I've a simple test application that requires the gfx_directx.dll backend to be in the same folder. It doesn't do anything but scroll a test screen to the left. Can you take a screenshot of it while it's running? (Use Alt-PrntScrn)