I have been wrestling with this issue intensively for three days now, and several different tutorials and searches still haven't helped. In my system Details, the processor is correctly identified as Intel, but after Graphics it just says NV126. I have a GeForce GTX 960 graphics card installed. No applications utilize the GeForce GTX 960 when they are run.
During my last attempt, I completely reinstalled Ubuntu 18.04. Then I ran
ubuntu-drivers devices which found my graphics card. After that I ran
sudo ubuntu-drivers autoinstall. Then I rebooted, checked in Software & Updates under the Additional drivers tab that the nvidia-driver-390 option was selected instead of the xserver-xorg-video-nouveau option.
But still in my system Details it just says that graphics are NV126, and the graphics card doesn't work.
What does NV126 mean? How can I get the system to use my graphics card?