This is guide, howto install NVIDIA CUDA Toolkit 12.1 on Ubuntu 21.10, 21.04, 20.04.3 LTS, 18.04.6 LTS / Debian 11, 10, Sid / Linux Mint 20.3, 20.2, 20.1. I assume here that you have installed NVIDIA drivers successfully using my earlier Install NVIDIA 495.xx Drivers on Debian / Ubuntu / Linux Mint Guide. You will need NVIDIA 495.xx drivers. As always remember backup important files before doing anything! Check video version of guide, Howto Install NVIDIA CUDA Toolkit 12.

2. Uninstall NVIDIA CUDA Toolkit 12.1 on Ubuntu 21.10 / Debian 11 / Linux Mint 20.3 2.1 Change root user su - ## OR ## sudo -i 2.2 Run NVIDIA CUDA Uninstall Script /usr/local/cuda/bin/cuda-uninstaller 2.3 Remove /etc/profile.d/cuda.sh rm /etc/profile.d/cuda.sh Then logout/login get NVIDIA CUDA away from PATH and LD_LIBRARY_PATH.