Every time I try to kill the x-server,
sudo service lightdm stop
so that I can install the latest Nvidia drivers, I get an error message.
stop: Unknown instance:
What am I doing wrong?
sudo service lightdm stop, lightdm and xserver should be stopped now (check with ctrl+alt+F7, which is your current xorg session, it should not show any desktop now)
sudo service lightdm startto start lightdm and xorg again.
Ok had the GTX 970 installation Problem under Ubuntu 14.04 too. Sometime i was able to start Ubuntu with the standart drivers and sometime not.
However, this should hopefully fix the Problem: After switching from IGP (I7 4770 with HD4600) to GTX970 in Biosi got an error with some Xorg Gui.
However you can not install the Nvidia-Driver while X is running: -> sudo killall Xorg solves the problem
Then -> sudo ./NVIDIA-x68xxx.run
After the first Driver Install (orig. Nvidia 352.xx) i had a blank screen. Then i run the Nvidia Driver Installer again -> sudo ./NVIDIA-x68xxx.run This second install told me some kind of noveu driver is running and should be disabled. The driver asked me if it should disable noveu -> Yes disable noveu
After restart: Et Voila lighdm is running again :)