How to install NVIDIA.run?

I have a Nvidia Ge force Ge6150 SE graphics card. I am running ubuntu 12.04. When I try to install the .run file it fails. It shows the message like this:

I tried to install it after uninstalling the old driver.still same message. Here is the log file:

nvidia-installer log file '/var/log/nvidia-installer.log'
creation time: Mon Jun 11 05:46:17 2012
installer version: 295.53

PATH: /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games

nvidia-installer command line:
    ./nvidia-installer

Using: nvidia-installer ncurses user interface
-> The file '/tmp/.X0-lock' exists and appears to contain the process ID '1062' of a >runnning X server.
ERROR: You appear to be running an X server; please exit X before installing.  For >further details, please see the section INSTALLING THE NVIDIA DRIVER in the README >available on the Linux driver download page at www.nvidia.com.
ERROR: Installation has failed.  Please see the file '/var/log/nvidia-installer.log' >for details.  You may find suggestions on fixing installation problems in the README >available on the Linux driver download page at www.nvidia.com.

but no such file is shown in the process manager.

As the error states, you are still running an X server. This error occurs when you try to install the Nvidia .run files while logged in.

Make sure you are logged out.

1. Hit Ctrl+Alt+F1 and login using your credentials.
2. kill your current X server session by typing sudo service lightdm stop or sudo lightdm stop
3. Enter runlevel 3 by typing sudo init 3
4. Install your *.run file.
   1. you change to the directory where you have downloaded the file by typing for instance cd Downloads. If it is in another directory, go there. Check if you see the file when you type ls NVIDIA*
   2. Make the file executable with chmod +x ./your-nvidia-file.run
   3. Execute the file with sudo ./your-nvidia-file.run
5. You might be required to reboot when the installation finishes. If not, run sudo service lightdm start or sudo start lightdm to start your X server again.
6. It's worth mentioning, that when installed this way, you'd have to redo the steps after each kernel update.

I installed latest nvidia drivers by this method:

sudo add-apt-repository ppa:ubuntu-x-swat/x-updates
sudo apt-get update
sudo apt-get install nvidia-current

It is working fine with unity 3d. Thanks to all.

Add the --no-x-check flag when you run this in the terminal:

sudo ./NVIDIAxxxx.run --no-x-check

I had the same problem installing the driver for an old GeForce 9800 GT in Ubuntu 14.04-2. It was the NVIDIA-Linux-x86_64-340.76.run

I switched to the the tty1 using Ctrl+Alt+F1 and also stopped the service lightdm and when running the executable got the same error .

What I did to solve the problem was navigate to the /tmp folder and erase the .X0-lock file.

You will only see it listed if you use ls -la as it is a hidden folder by default(that is why it has a dot in front of the name)

cd /tmp
rm -rf .X0-lock

After erasing that folder and executing the NVIDIA-Linux-x86_64-340.76.run it installed just fine.

This instructions Works great under ubuntu server 12.04 with ubuntu desktop for nvidia 8400GS PCI 512MB too just need to unistall all previous versions of default versions under ubuntu like 173 etc or any other before installing or there will be conflict or crash. Follow this tread instructions + read me install info from your card model example in my case latest driver version 319.23, see link below:

http://us.download.nvidia.com/XFree86/Linux-x86/319.23/README/installdriver.html