Nvidia drivers - Second GPU not working

[jrwagh333]

I have updated to the latest stable Nvidia drivers.

I am using Windows 8.1 with a GTX 680 which I have my main monitor plugged in to.
I also have an old 8400GS that I use to plug two other monitors in to that I just use for web browsing and documents.

Since installing the latest drivers, the 8400 isn't detected.
the 8400 is detected in the BIOS and is also listed as a Microsoft Display Adapter under Device Monitor.

I have tried re-installing the driver but still no luck.
CPUZ detects the 680 and also another GPU (the 8400) but just as a generic graphics card.

 

[Shiari]

According to the releate info the drivers don't support that card anymore, you need to go down to a 340.xx series driver.