I followed these steps to install nvidia driver 440 in ubuntu system of version 16.04. My graphics card model is nvidia GeForce GTX 1080
sudo add-apt-repository ppa:graphics-drivers/ppa
sudo apt-get update
When I do ubuntu-drivers devices
It shows like
== /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0 ==
manual_install: True
modalias : pci:v000010DEd00001B80sv000010DEsd0000119Ebc03sc00i00
vendor : NVIDIA Corporation
driver : nvidia-430 - third-party free recommended
driver : nvidia-415 - third-party free
driver : xserver-xorg-video-nouveau - distro free builtin
driver : nvidia-418 - third-party free
driver : nvidia-410 - third-party free
driver : nvidia-384 - distro non-free
In the above output the driver 440 is not present.
sudo apt-get install nvidia-440
The output of the above line is
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package nvidia-440 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'nvidia-440' has no installation candidate