Bonjour Xubu1957, merci à toi! Alors voici les retours:
sylpaf@sylpaf-MS-7597:~$ lspci -vnn | grep -A12 '\''[030[02]\]' | grep -Ei "vga|3d|display|kernel"
02:00.0 VGA compatible controller [0300]: NVIDIA Corporation GK208B [GeForce GT 730] [10de:1287] (rev a1) (prog-if 00 [VGA controller])
Kernel modules: nvidiafb, nouveau
sylpaf@sylpaf-MS-7597:~$
sylpaf@sylpaf-MS-7597:~$ ubuntu-drivers devices
WARNING:root:_pkg_get_support nvidia-driver-455: package has invalid Support Betaheader, cannot determine support level
== /sys/devices/pci0000:00/0000:00:09.0/0000:02:00.0 ==
modalias : pci:v000010DEd00001287sv000010DEsd00001287bc03sc00i00
vendor : NVIDIA Corporation
model : GK208B [GeForce GT 730]
driver : nvidia-driver-390 - distro non-free
driver : nvidia-driver-440-server - distro non-free
driver : nvidia-driver-435 - distro non-free
driver : nvidia-driver-418-server - distro non-free
driver : nvidia-driver-455 - third-party free recommended
driver : nvidia-340 - distro non-free
driver : nvidia-driver-450-server - distro non-free
driver : nvidia-driver-450 - distro non-free
driver : xserver-xorg-video-nouveau - distro free builtin
sylpaf@sylpaf-MS-7597:~$ uname -a
Linux sylpaf-MS-7597 5.4.0-49-generic #53-Ubuntu SMP Fri Sep 18 09:54:57 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
sylpaf@sylpaf-MS-7597:~$ dpkg -l | grep nvidia
ii libnvidia-common-450 450.66-0ubuntu0.20.04.1 all Shared files used by the NVIDIA libraries
rc libnvidia-compute-390:amd64 390.138-0ubuntu0.20.04.1 amd64 NVIDIA libcompute package
rc libnvidia-compute-390:i386 390.138-0ubuntu0.20.04.1 i386 NVIDIA libcompute package
rc libnvidia-compute-435:amd64 435.21-0ubuntu7 amd64 NVIDIA libcompute package
rc libnvidia-compute-450:amd64 450.66-0ubuntu0.20.04.1 amd64 NVIDIA libcompute package
ii libnvidia-compute-450:i386 450.66-0ubuntu0.20.04.1 i386 NVIDIA libcompute package
rc libnvidia-compute-450-server:amd64 450.51.06-0ubuntu0.20.04.2 amd64 NVIDIA libcompute package
ii libnvidia-decode-450:i386 450.66-0ubuntu0.20.04.1 i386 NVIDIA Video Decoding runtime libraries
ii libnvidia-encode-450:i386 450.66-0ubuntu0.20.04.1 i386 NVENC Video Encoding runtime library
ii libnvidia-fbc1-450:i386 450.66-0ubuntu0.20.04.1 i386 NVIDIA OpenGL-based Framebuffer Capture runtime library
ii libnvidia-gl-450:i386 450.66-0ubuntu0.20.04.1 i386 NVIDIA OpenGL/GLX/EGL/GLES GLVND libraries and Vulkan ICD
ii libnvidia-ifr1-450:i386 450.66-0ubuntu0.20.04.1 i386 NVIDIA OpenGL-based Inband Frame Readback runtime library
rc nvidia-367 375.82-0ubuntu3 amd64 Transitional package for nvidia-375
rc nvidia-375 384.130-0ubuntu0.16.04.2 amd64 Transitional package for nvidia-384
rc nvidia-384 390.138-0ubuntu0.20.04.1 amd64 Transitional package for nvidia-driver-390
rc nvidia-compute-utils-390 390.138-0ubuntu0.20.04.1 amd64 NVIDIA compute utilities
rc nvidia-compute-utils-435 435.21-0ubuntu7 amd64 NVIDIA compute utilities
rc nvidia-compute-utils-450 450.66-0ubuntu0.20.04.1 amd64 NVIDIA compute utilities
rc nvidia-compute-utils-450-server 450.51.06-0ubuntu0.20.04.2 amd64 NVIDIA compute utilities
rc nvidia-dkms-390 390.138-0ubuntu0.20.04.1 amd64 NVIDIA DKMS package
rc nvidia-dkms-435 435.21-0ubuntu7 amd64 NVIDIA DKMS package
rc nvidia-dkms-450 450.66-0ubuntu0.20.04.1 amd64 NVIDIA DKMS package
rc nvidia-dkms-450-server 450.51.06-0ubuntu0.20.04.2 amd64 NVIDIA DKMS package
rc nvidia-kernel-common-390 390.138-0ubuntu0.20.04.1 amd64 Shared files used with the kernel module
rc nvidia-kernel-common-435 435.21-0ubuntu7 amd64 Shared files used with the kernel module
rc nvidia-kernel-common-450 450.66-0ubuntu0.20.04.1 amd64 Shared files used with the kernel module
rc nvidia-kernel-common-450-server 450.51.06-0ubuntu0.20.04.2 amd64 Shared files used with the kernel module
ii nvidia-prime 0.8.14 all Tools to enable NVIDIA's Prime
ii nvidia-settings 440.82-0ubuntu0.20.04.1 amd64 Tool for configuring the NVIDIA graphics driver
ii screen-resolution-extra 0.18build1 all Extension for the nvidia-settings control panel
sylpaf@sylpaf-MS-7597:~$ dpkg -l | grep -v ^ii
Souhait=inconnU/Installé/suppRimé/Purgé/H=à garder
| État=Non/Installé/fichier-Config/dépaqUeté/échec-conFig/H=semi-installé/W=attend-traitement-déclenchements
|/ Err?=(aucune)/besoin Réinstallation (État,Err: majuscule=mauvais)
||/ Nom Version Architecture Description
+++-==========================================-===================================================-============-======================================================================================================
rc libnvidia-compute-390:amd64 390.138-0ubuntu0.20.04.1 amd64 NVIDIA libcompute package
rc libnvidia-compute-390:i386 390.138-0ubuntu0.20.04.1 i386 NVIDIA libcompute package
rc libnvidia-compute-435:amd64 435.21-0ubuntu7 amd64 NVIDIA libcompute package
rc libnvidia-compute-450:amd64 450.66-0ubuntu0.20.04.1 amd64 NVIDIA libcompute package
rc libnvidia-compute-450-server:amd64 450.51.06-0ubuntu0.20.04.2 amd64 NVIDIA libcompute package
rc nvidia-367 375.82-0ubuntu3 amd64 Transitional package for nvidia-375
rc nvidia-375 384.130-0ubuntu0.16.04.2 amd64 Transitional package for nvidia-384
rc nvidia-384 390.138-0ubuntu0.20.04.1 amd64 Transitional package for nvidia-driver-390
rc nvidia-compute-utils-390 390.138-0ubuntu0.20.04.1 amd64 NVIDIA compute utilities
rc nvidia-compute-utils-435 435.21-0ubuntu7 amd64 NVIDIA compute utilities
rc nvidia-compute-utils-450 450.66-0ubuntu0.20.04.1 amd64 NVIDIA compute utilities
rc nvidia-compute-utils-450-server 450.51.06-0ubuntu0.20.04.2 amd64 NVIDIA compute utilities
rc nvidia-dkms-390 390.138-0ubuntu0.20.04.1 amd64 NVIDIA DKMS package
rc nvidia-dkms-435 435.21-0ubuntu7 amd64 NVIDIA DKMS package
rc nvidia-dkms-450 450.66-0ubuntu0.20.04.1 amd64 NVIDIA DKMS package
rc nvidia-dkms-450-server 450.51.06-0ubuntu0.20.04.2 amd64 NVIDIA DKMS package
rc nvidia-kernel-common-390 390.138-0ubuntu0.20.04.1 amd64 Shared files used with the kernel module
rc nvidia-kernel-common-435 435.21-0ubuntu7 amd64 Shared files used with the kernel module
rc nvidia-kernel-common-450 450.66-0ubuntu0.20.04.1 amd64 Shared files used with the kernel module
rc nvidia-kernel-common-450-server 450.51.06-0ubuntu0.20.04.2 amd64 Shared files used with the kernel module
sylpaf@sylpaf-MS-7597:~$
Pour le lien que tu indiques, je l'avais suivi, j'ai tenté un certain nombre de manips décrites mais rien n'y a fait...