Although it’s always better to run Ubuntu on a new machine and experience the lightening fast way that it relates to new hardware, if you happen to have an old machine upon which you have installed Ubuntu 14.04 you may have experienced a nasty freeze after you login.
I spent many hours trying this and that. I guessed it was something to do with a video card or a video card driver (proprietary? Nvidia brand?). Finally, this command made the dumb machine bow the knee in submission:
sudo apt-get install nvidia-current
Before trying this command, I had also tried these commands found in this blog below. Perhaps they will aid you? Keep them handy for reference as it also instructs how to reach the terminal when you freeze:
Oh, also, I haven’t tried since, but I think I recall the only way I was able to access my terminal was by doing control+alt+F2 somewhere between boot and the regular graphical login screen…