To answer your question first, you are using the open source nouveau
and not the NVIDIA drivers. This means that your attempt to install the proprietary NVIDIA drivers failed for whatever reason. If you want to use the NVIDIA drivers - use a different method from how you tried it by using the GUI.
First completely uninstall the NVIDIA drivers which you have tried to install in your attempt before.
Start the laptop, mark the Ubuntu entry in the GRUB boot menu and then press the E key.
Add nouveau.modeset=0
at the end of the linux
line. Press the F10 key to boot the system.
Do not miss to set a Space between the last letter in the linux
line and nouveau.modeset=0
.
When the login screen appears press Ctrl+Alt+F1. Enter user name and password - execute :
sudo apt purge nvidia*
sudo reboot
Now install the latest stable NVIDIA drivers 378.13 and nvidia-prime
from the GPU Drivers PPA.
After the restart mark the Ubuntu entry in the GRUB boot menu again and press the E key.
Add nouveau.modeset=0
at the end of the linux
line. Press the F10 key to boot the system.
Do not miss to set a Space between the last letter in the linux
line and nouveau.modeset=0
.
When the login screen appears press Ctrl+Alt+F1. Enter user name and password - execute :
sudo add-apt-repository ppa:graphics-drivers/ppa
sudo apt update
sudo apt install nvidia-378 nvidia-prime
sudo reboot
Execute lspci -k | grep -EA2 'VGA|3D'
... now you'd see : Kernel driver in use: nvidia
In case you still have problems to get the NVIDIA drivers working, you should consider to opt-in to the Ubuntu LTS enablement stacks, which provide newer kernel and X support for existing Ubuntu LTS releases. This could generally be a good idea, because you are having a quite new notebook. Opt-in to the Ubuntu 16.04 LTS - HWE - enablement stacks by executing the following command :
sudo apt install --install-recommends linux-generic-hwe-16.04 xserver-xorg-hwe-16.04
sudo reboot
Before you perform it, remove all NVIDIA software as described in step 1 and reinstall the drivers as described in step 2 after you have installed the new kernel and rebooted the operating system.
Additional information : Boot into the BIOS to make sure that Secure Boot is disabled and that the NVIDIA graphics chip and NVIDIA Optimus are enabled (in some machines this option is available).