please read
try at your own risk,I have read that there are some bugs,I have never had a problem with Nvidia proprietary drivers but you might.
the taring you see is from the recorder I'm using.
remove the nouveau driver by starting "Additional Drivers" and hit remove
you can install the one in the repos the same way as you see in the video.
if you need to remove and go back to nouveau,remove
nvidia-current nvidia-current-modaliases nvidia-settings
and reinstall nouveau
you can install a newer driver with a ppa but that is up to you.
sudo add-apt-repository ppa:ubuntu-x-swat/x-updates
sudo apt-get update
sudo apt-get install nvidia-current nvidia-current-modaliases nvidia-settings
if you have problems with the ppa you can login in save mode and run
sudo ppa-purge ppa:ubuntu-x-swat/x-updates
and reinstall nouveau.