I am using UBUNTU 14.04.2 on my lenovo E531 laptop.My problem is: after booting the computer,graphical interface of ubuntu fails to start and it shows a black screen. I'd consider myself a beginner, but I know how to use terminal commands on the TTY screen a little bit. I appreciate any help/guidance in advance.
Update: i have tried lots of different methods but the result is :failure :-( i installed gnome shell : http://itsfoss.com/how-to-install-gnome-in-ubuntu-14-04/ but at the end the black screen is all i have i also tried this method : Blank screen after installing nvidia restricted driver but the result was not helpful again
my Nvidia driver is Nvidia-331, and it was working fine before this problem