After a software update through the GUI software update tool, my machine always boots into an error screen noting:
The system is running in low graphics mode Your screen, graphics card, and input device settings could not be detected correctly. You will need to configure these yourself.
I did find this thread somewhat useful, but there is not much information on how to fix for Intel graphics. My machine is a Dell Optiplex 9020 with Integrated Intel HD Graphics 4600. I am running Ubuntu 14.04.
So far I've tried several approaches, based on things I've read in other threads:
sudo apt-get install ubuntu-desktop
- adding the Xorg-Edgers PPA.
sudo apt-get install xserver-xorg-video-intel
sudo apt-get install xserver-xorg-lts-trusty
sudo apt-get install mesa-utils