after installing 14.04 on my plain notebook (ThinkPad L430 with NVS5400M Graphic-Card) I also wanted to install the nvidia drivers. I did this via the GUI in the System administration. (as decribed here Ubuntu won't login after installing nvidia drivers ) I tried version 331.38 as well as 304.117. Unfortunately I was not able to log on the unity any more after rebooting the system. It remained just purple. So I went to the shell and de-installed the nvidia driver manually. After that everything was fine again. But the problem is, that the computer is quite slow without the drivers and has micro-freezes from time to time.
Has anybody an idea, how I can find out what causes the error? Or has anybody had a similar problem? Or any idea how I can install the driver?