Before switching to the nvidia drivers you need to install linux-source and linux-headers (see bug 1068341). After the source is installed, try switching to the nvidia drivers.
Here is how:
Before you start, install all updates (and reboot the computer, if you are told to).
Switch to a terminal (
Login as your username.
Install linux source (
sudo apt-get install linux-source) and headers (
sudo apt-get install linux-headers-generic).
Uninstall nvidia driver - this depends on which version you installed (
sudo apt-get remove nvidia-current or
sudo apt-get remove nvidia-current-updates or
sudo apt-get remove nvidia-experimental-304).
Reinstall nvidia driver (
sudo apt-get install nvidia-current-updates).
If it successfully installs, restart the computer (
sudo shutdown -r now).
More In-depth How-to
The following link gives a more in-depth overview on how to handle the nvidia driver. It should be applicable to more cases, that are similar, but not exactly the same as the one described here: