Hi Cepheus
I missed your latest message.
I tried
and got an error message
This is strange, because I thought I was using nvidia version 331

any attempt to reinstall nvidia_304_updates vis Synaptic ends up with an error.
I cant seem to get rid of nvidia_304, it always pops up with the modprobe call suggested, even if I have tried to uninstall it with synaptic.
I thought version 331 might be better.

Something has eaten my message... Anyway: "No such device" means it claims to not find the hardware. Can you

and post the result?

Hi Cepheus
Here is the result of lscpi

Ok there it is:

Searching for "NVIDIA Corporation Device 1380" suggests that this is actually a GTX 750 Ti, but I'm no expert on these numbers.

550 Ti should be supported by your driver version.
750 Ti is not, it is supported by 334.21 or higher.

Good point!
Yes, I have lost the box, I could open up my PC.
I do know that the card has the very latest Nvidia architecture and is
Cuda Capability 5.0
I did find a very recent driver a few weeks ago but as a run file.
would not that mean shutting down X?
I have not managed to do that.

I would generally advise against executing the script from nvidia, because if it fails, or becomes obsolete by future updates, it is complicated to remove the remnants and get a working system again. However, the latest ubuntu-packaged driver is something 331 which is not current enough: https://launchpad.net/ubuntu/+search?text=nvidia.

However, I have found this, so if you're brave or have backups:

http://ubuntuhandbook.org/index.php/...-ubuntu-linux/

Thankyou for all your help.
Earlier I did try stopping the X server with the same command as in the article.
However, much to my surprise I dont get the impression I go into text mode as I see no command prompt and no output from any of the basic commands.
I see the echo of my entered commands however, and shutdown -H now seems to have worked!

Hi Cepheus
Well, I had a shot at version 334 and my system appears to be working much better now.
Here are some salient points:
I typed Control-Alt-F1 to get into full screen.
Then I killed the X server from within that: sudo service lightdm stop.
I was still in text mode, so my previous worry was removed.
Then I tried sudo ./NVidia-Linux-x86-334.31.run
The first time round it failed , I tried again, it told me my gcc was the wrong version (4.8.1) instead of 4.6.
So I changed the symbolic link on gcc: ls -s gcc-4.6 gcc
I then ran the script and I declined the running with DPKMS (probably a bad idea on my part)
But I ran into no further errors.
Now my screen has a nice high resolution, without any manual configuration from me.

Sounds good. To confirm the nvidia driver is running, you can install the package "mesa-utils" in software center (if not already installed), and type "glxinfo|head" in a console window. It should say something like "glx vendor string: NVidia Corporation".

that was not the normal way to install the nvidia drivers.

in ubuntu in settings you have additional drivers which will find the proprietary nvidia drivers for your system and they work best. install and use them

or

to install the nvidia binary drivers. typically you download the binary, right click it and make it executable and then do a alt-F1 to drop to a shell and login. issue a /etc/init.d/gdm stop or whatever wm you are running. (Cannot recall the right command but google it to stop the display manager) and navigate to the downloaded location of the file and type it out to run it.

from past experience with Ubuntu. also down load nvidia-xconfig. and run it, this will create the correct xorg.conf file.

also uninstall bumblebee if it installs. that prevents the system from booting the nvidia driver. (bumblebee might be fixed now)

my two cents

That's what I did!

To me this process seems to have become overly complicated.
To install the NVIDIA drivers on Ubuntu the best way is to use either jockey or the software centre. With a card of that age you should be fine using the newest driver available from the Ubuntu repository and using the driver from the repository should mean that when the kernel is updated you don't find yourself booting into a blank black screen.
Once the driver has been installed and you have rebooted (it is vital you either reboot or restart X11 to apply the driver and rebooting is much simpler) you should then run nvidia-settings using sudo, set the resolution and other settings you require then (in X Server Display Configuration) click "Save to X Configuration file).
There are other ways to do this I am sure but the above has always worked for me when other things have failed or caused issues and is based upon the Ubuntu and Debian NVIDIA driver installation guides.

It's a 750 Ti, only a few months old.

Ah, sorry, you had said it was a 550 Ti which is of an age which should be well supported by Ubuntu.