But I installed 396...

Do I need to uninstall the other one?
How do you do that?

RATS! So close...

I just go this long post with directions...

Following....

Up above,

CUDA driver version is insufficient for CUDA runtime version.

So, 396 is in your Home folder with the Execute bit Set.

Close Any Open Apps.
Hold down the Keys Ctrl, ALT, F1 to enter the console mode.
Log In
Type, sudo service lightdm stop
Enter Password,
Once it's stopped, Enter,
sudo apt-get remove --purge nvidia*
YES, include the asterisk.
Then,
sudo apt-get autoremove
That should remove the repository driver.
Enter, dir
That will list the contents of Home, you should see the 396 driver there.
Enter,
sudo ./NVIDIA-Linux-x86_64-396.54.run
Respond to the Screen prompts,
The install script will Always fail if you don't provide one, it means nothing, continue installing.
You probably don't even have 32-bit compat, keep going.
You Want To Register the Module, chose Yes.
Since you don't have a custom xorg.conf, let it build one for you.
After it's done, sudo reboot
You might have to find nVidia Settings again, see what says for a driver version.

Everything worked as you said it would except this...

sudo ./NVIDIA-Linux-x86_64-396.54.run

Do You Have the Driver in your Home folder?
When you enter dir, you should see the driver named there.
If the driver is there, it should work.
What do you get instead of it working?

sudo: ./NVIDIA-Linux-x86_64-396.54.run: command not found

After DIR, I DO see the file.

After DIR...

david@MINER:~$ dir
BOINC Documents Music Public
BOINC.7z Downloads NVIDIA-Linux-x86_64-396.54.run Templates
Desktop examples.desktop Pictures Videos

The driver is definitely in my home folder...

command not found

Sounds as though the Execute bit is Not set.
Right Click on the file, select Properties/Permissions and check the box 'Execute'.

This seems to work from the terminal to set the bit;
sudo chmod +x NVIDIA-Linux-x86_64-396.54.run
or maybe, sudo chmod +x /home/username/NVIDIA-Linux-x86_64-396.54.run

That did it!

Spoke too soon.
It ran but it came up with a message that said something like, "It appears you are running an X-server and that wont work... blah blah blah...

"Please exit X before installing...

Apparently you didn't follow that instruction either.
To Stop the X-Server, run;
sudo sevice lightdm stop

You Are in the Console mode...right?
I suggest you run the two commands to uninstall the Repository driver again as well. If you don't remove the Repository driver First, your system will be Borked after installing the nVidia driver. Also, don't install the Repository driver if the Driver from nVidia is installed. I think nvidia-uninstall will remove the driver from nVidia, or, sudo ./NVIDIA-Linux-x86_64-396.54.run --uninstall

I see. It didnt work the first time because the execute bit wasnt set. Now I go back and stop the x-server...
Thanks teacher!

Yes in console...
Now it runs but stops at "The Nouveau kernel driver is currently in use by your system. This driver is incompatible with NVIDIA and must be disabled before proceeding....

CRUD!

It tried to make the file to disable the driver but failed.
I read how to do it on the net... Will try maybe the restart did it?

That happened because you rebooted after uninstalling the Repository driver. If you would have followed the instructions none of this would have happened. ;-(
The easiest way if blacklisting doesn't work is to re-install the 384 driver from additional drivers. That will disable nouveau. Then go back and follow the instructions again. Drop into console, stop lightdm, remove the Repository driver, then install the 396 driver.

So install the NVID driver from the updates, that will disable this nouveau thing and then FOLLOW the instructions...

You must be a Linux master....
I'm not worthy!