Cannot properly boot into Ubuntu after installation of Nvidia driver

I had a similar problem. Solved like this:

1. Boot as normal and get to login screen

2. press Ctrl + Alt + F1

3. Login with your username and password.

4. type sudo stop lightdm and press enter, stops X11

5. type sudo apt-get purge nvidia* and press enter -clears all nvidia items

6. type sudo apt-get install xserver-xorg-video-nouveau and press enter- will install this package or tell you if it is already there.

7. type sudo reboot

this got me back up and running (although no icons in unity launcher - since need correct graphic drivers) check system settings to search for Additional drivers to see if this cab be addressed - although adding wrong drivers may cause the system to be faulty or freeze after login.

Try removing your freshly installed Nvidia driver and go back to the open-source driver, Nouveau. Log in to the command line interface of Ubuntu, launch sudo apt-get install nouveau-firmware (just in case) then follow the instructions at https://askubuntu.com/a/12941/5592:

To reconfigure xorg.conf, type the following command:

sudo dpkg-reconfigure xserver-xorg

Go following the screen steps, answering the wizard questions and you should able to restore or reconfigure to previous Nouveau state.

After that, if this solved your problem, you will probably have a very low resolution. So launch the "Displays" utility from the Dash home and adjust your resolution accordingly to fit your screen the best.