How to install the Nvidia 340 driver on Debian?

This guide has been tested on an installation of Linux Mint Debian Edition, but it should work on Debian itself or on any distributions based on Debian.

Checking what Nvidia driver you need

Install and run nvidia-detect:

apt install nvidia-detect

If the output mention that you need to install nvidia-legacy-340xx-driver, this guide is for you.

Removing every old Nvidia driver (including Nouveau)

We now have to remove every other Nvidia drivers so that the system correctly use the Nvidia 340 driver.

apt purge nvidia.

Note the . after nvidia

Install the Nvidia 340 driver

apt install nvidia-legacy-340xx-driver