Installing the NVIDIA driver manually through the manufacturer's website is generally not recommended and can hose a system pretty quickly. There's not really a good solution to completely remove NVIDIA traces created by the .run
file so I suggest that you do a reinstall of Ubuntu before trying anything further, I think you should probably go with Ubuntu 22.04
LTS as it is generally supported for much longer than the intermediate 2x.10
releases which tend to be slightly more stable.
The latest driver that the NVIDIA K2100M
supports seems to be provided by the nvidia-driver-470
package in Ubuntu. After a fresh install, issue the command to install it:
sudo apt install nvidia-driver-470