I am using a Lenovo W530 with a NVIDIA Quadro K1000M 2GB. Yesterday after upgrading from Ubuntu 12.04 to 14.04 LTS, my laptop failed to restart. Specifically, it would get stuck at the splash screen with the 5 dots blinking under the Ubuntu logo. If I press the esc key and go to the diagnostic screen, I would see the last line saying
Starting CUPS printing spooler/server [OK]
After looking at various suggestions (and following many of them without any difference) I finally suspected that it could be because of the NVIDIA drivers and tried to boot it using the nomodeset. That did not solve the problem except that the last few lines in the diagnostic screen now says
Starting Mount network filesystems [OK]
Stopping Mount network filesystems [OK]
Stopping LightDM Display Manager [OK]
Starting CUPS printing spooler/server [OK]
Starting Mount network filesystems [OK]
Stopping Mount network filesystems [OK]
Starting Mount network filesystems [OK]
Stopping Mount network filesystems [OK]
Sorry, I don't know much about linux and any help would be much appreciated. Thanks in advance.