I selected one of the alternative NVIDIA drivers on my Sony Vaio from the Additional Drivers application. That ruined my installation and all I get is the login prompt at bootup.
However I can go in at bootup by selecting "Older Ubuntu Versions" and selecting whatever was there before. This older version has the correct drivers (NVIDIA accelerated graphics driver 173) which I'm using right now.
Is there file in the "new" (broken) system where I can replace the NVIDIA driver entry from the "old" system I'm using (which works fine) without having to reinstall UBUNTU from scratch? Or can I reinstall UBUNTU without losing all my files and settings? or what are my alternatives?