Driver: Installation Failed
You may find this error message while trying to set up the NVIDIA CUDA Toolkit in Ubuntu.
I found it when I was installing the toolkit for ArrayFire
 CUDA Toolkit Installation
1. Download the CUDA Toolkit in the link.
2. Extract the .run file in a location
sudo sh cuda_5.0.35_linux_64_ubuntu11.10-1.run --extract <location>
3. Exit the X server (press Ctrl+Alt+F1) and stop the display manager by the following command.
sudo stop lightdm
4. cd to the location and now there are run files named samples*, devdriver* and cudatoolkit*.
5. Install devdriver (*only if NVIDIA Driver is not installed)
sudo sh devdriver_5.0_linux_64_304.54.run
6. Install cudatoolkit
sudo sh cudatoolkit-5.0.35_linux_64_ubuntu11.10.run
In the end, when it asks "Would you like to create a symbolic link /usr/local/cuda/ pointing to /usr/local/cuda-x.x?", you must enter (y)es.
If it didn't ask, or you didn't enter (y)es, enter the following command to create a symbolic link.
ln -s /usr/local/cuda-x.0 ./usr/local/cuda
7. Install sample (*optional)
sudo sh cuda-samples_5.0.35_linux.run
8. Reboot your machine
 ArrayFire Installation
2. Unzip arrayfire in /usr/local
sudo unzip ArrayFire*.zip -d /usr/local
 Environmental Variables Setting
1. Open bash setting
2. Add the following lines in the end (probably only need to set LD_LIBRARY_PATH)
export AF_PATH=/usr/local/arrayfire export CUDA=/usr/local/cuda export PATH=/usr/local/cuda/bin:$PATH export LD_LIBRARY_PATH=/usr/local/cuda/lib:/usr/local/cuda/lib64:/lib64:$LD_LIBRARY_PATH
3. Reload bash setting
Note: This may not work in laptops with optimus