If you are trying to install nVidia drivers from their website you might receive the following error
ERROR: Unable to load the kernel module ‘nvidia.ko’. This happens most frequently when this kernel module was built against the wrong or improperly configured kernel sources, with a version of gcc that differs from the one used to build the target kernel, or if a driver such as rivafb/nvidiafb is present and prevents the NVIDIA kernel module from obtaining ownership of the NVIDIA graphics device(s), or NVIDIA GPU installed in this system is not supported by this NVIDIA Linux graphics driver release.
To fix the above error message use the following procedure
1) Download Newest Nvidia drivers from here
2) Open module blacklist as admin
gksudo gedit /etc/modprobe.d/blacklist.conf
Add these lines and save:
blacklist vga16fb
blacklist nouveau
blacklist rivafb
blacklist nvidiafb
blacklist rivatv
3) Uninstall any previously installed Nvidia drivers:
sudo apt-get --purge remove nvidia-*
4) Reboot your computer
5) When an error message pops up saying that Ubuntu cannot load Nvidia drivers, choose Exit to terminal (Exit to console)
6) Login and cd to the directory where you saved your file
7)Install drivers
sudo sh NVIDIA-Linux-x86_64-195.36.24-pkg2.run
8)Start GDM
sudo service gdm start