I have a very annoying issue. For the last 10 hours or so, I have been trying to install CUDA 7.0 on the most recent version of Ubuntu 14.04. My computer is a laptop with a Geforce 980M and Intel integrated graphics (forget the version). I did a fresh installation of Ubuntu, installed CUDA in accordance with the instructions on the website, and blacklisted the Nouveau drivers just to be safe
.
However, when I try to boot, it hangs at the splash screen. The only solution to this is to boot into the previous kernel (which loads properly, although without CUDA), then reboot into the current kernel(which will then load properly).
I got it working once by accident, then tried to install pycuda and broke it.

I desperately need help. I have tried modifying all sorts of files, and nothing seems to work, unless by work one means "prevents the splash screen from showing up at all."

Welcome to LQ.

You didn't tell what your purpose of CUDA is ? ?

HOWTO Nvidia drivers : 1) Install Ubuntu 14.04.3 .
2) Select : "System Settings->Software & Updates->Additional Drivers"
... or a similar entry in the Menu.
... May vary with different window managers, { Mate, Gnome etc. }.
The program "Additional Drivers" will automatically install 'Nvidia drivers'
.. And of course do all the editing to disable 'Nouveau',,, automatically.


If you then think you need any CUDA for development :
Install Synaptic : $ sudo apt-get update && sudo apt-get install synaptic
... and all the CUDA should be visible when you open the Synaptic Package Manager.
( $ sudo synaptic )
14.04 CUDA packages http://packages.ubuntu.com/search?su...&keywords=cuda
14.04 Updates, CUDA http://packages.ubuntu.com/search?su...&keywords=cuda


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I would rather avoid reinstalling the system, since I have gotten to a point at which many things are working properly. In addition, installing the Toolkit and drivers separately has never really worked for me on this device. I was hoping someone might recognize the behavior (need to switch kernels to boot). I am certain that it is Nouveau's fault somehow. I also think it must have to do with something that is not unloaded properly when Ubuntu reboots, otherwise a reboot would reset it to its initial state. Or maybe it is something fro the previous kernel that is not unloaded that helps it boot, I don't know.

My problem seems quite similar to the one mentioned here (http://codeyarns.com/2015/03/30/nvid...-linux-kernel/),
in that it hangs at the bootup screen, and booting into another Ubuntu instance can allow boot.
However, the solution given there does not work for me.