I think this needs a little more information before people can help you - maybe someone can answer.

First, I'm not sure why you're doing INF modding, but maybe back off from that until you can solve these other problems.

Second, let me ask for a bit of clarification here on drivers, BIOS, and the whitescreen:

Are you saying that, when you install v340.62 of the nVidia drivers for the 680M, THEN if you go into the BIOS and enable onboard audio, the screen goes white?

When does the screen go white?  After the POST, after a Windows "loading" screen (Windows Logo, spinning dots), at the login screen, after logging in, at random?

Last, when the screen goes white, have you tried connecting an external monitor?

INF file is required for installing NV drivers.

No for 680M. This driver: https://www.nvidia.com/download/driverResults.aspx/78431/en-us

After installing this driver and after enable Onboard audio, screen goes to white after boot Windows - so Windows logo with spinning dots and after this, screen is white (sometimes pink and green).

I don't try external monitor at the moment of white death. I will try it.

Hello , 

did it work when you connected to another mon!? 

No, still onboard audio is disabled. When I enable it, white death.