Ok, so you are experiencing something that happens to a small group, me included. The solution is a little bit tedious but if you have an internet connection then we can proceed.
Another point to be noted, if you are trying to install the driver into a optimus/hybrid graphics enabled laptop/All in one, you may stuck at black screen or low resolution (or some weird situation).
These nvidia-driver doesn't support optimus enabled computer. To know how to work with these models see How well do laptops with Nvidia Optimus work?.
To know whether you have optimus, execute
lspci | grep VGA, if the output is two line
intel HD and
nvidia, you do have optimus. If you only have one nvidia card in the output, please follow instruction below.
First, when booting, hold the SHIFT or press ESC like crazy until the GRUB menu appears. Select the option about "Recovery".
After the recovery menu appears, go to the option that gives you the chance to go to the terminal with root privileges.
After going to the terminal add the Xorg Edges PPA. Why this PPA?, Because on some machines I have worked on, the solution is the specific drivers and xorg version found in this PPA.
sudo add-apt-repository ppa:xorg-edgers/ppa
sudo apt-get update
sudo apt-get upgrade
Now the following line, which is the one to install a specific driver, depends totally on the video card you are using.
This will literally vary, for example, if you have an Nvidia 730m from HP DV 6000 for example, the only driver that will work correctly will be the oldest one. This is, the Nvidia 173 packages.
If you have a more up to date model, then you can test the 304, 310 or 313 series.
simply do ONE of the following and reboot afterwards to see if it worked:
sudo apt-get install nvidia-173 - For very old models ranging from 5xxx to 9xxx
sudo apt-get install nvidia-304 - For old/new models ranging from 6xxx and up
sudo apt-get install nvidia-310 - For new models
sudo apt-get install nvidia-313 - For newest models
After executing one of those, simply do
One of those will, after rebooting, fix all problems. Unity and Compiz should work correctly. The only thing left would be that, if after opening the Nvidia Panel you get an error about some missing file, simply go to a terminal and
sudo nvidia-xconfig, then reboot again.
This is the quickest way to solve this, although,adding the specific Nvidia model would help narrow down the package you need to install. I can confirm this in 12.04, 12.10 and 13.04 with about 10 computers that happen to have the same problem since I encounter it a couple of months back.