Hello,

I am running Debian 9 on a laptop that has both the integrated gpu and a nvidia graphics card. For battery saving purposes I figured that I should get the nvidia drivers. After quite unsuccessfully trying to install the drivers from nvidias website, then understanding I should not use their web site and instead do it as the debian wiki says.
I think I ended up in some kind of mess with my nvidia driver, so here's the situation right now. Whenever I try to install a new package, simply update my system (or do any apt-get command), the terminal returns this : "E: dpkg was interrupted, you must manually run 'sudo dpkg --configue -a' ". So i do that command, and it shows a box saying this :

The nvidia-installer program was found on this system. This is probably left over from an earlier installation of the non-free NVIDIA graphics driver, installed using the NVIDIA *.run file directly. This installation is incompatible with the debian packages. To install the Debian packages safely, it is therefore necessary to undo the changes performed by nvidia-installer.

Run "nvidia-installer --uninstall"? (Yes or No)

I select yes, and then it shows the following text :

Welcome to NVIDIA Software Installer for Unix/Linux

Detected 8 CPUs online; setting concurrency level to 8.

If you plan to no longer use the NVIDIA driver, you should make sure that no X screens are configured to use the NVIDIA X driver in your X configuration file. If you used nvidia-xconfig to configure X, it may have created a backup of your original configuration. Would you like to run 'nvidia-xconfig --restore-original-backup' to attempt restoration of the original X configuration file?
[default: (N)o]:

Now here comes the weird part and why I posted this. No matter what I type, N, No, Y, Yes, anything really, after I hit enter, it does nothing. It allows me to keep typing, I can go to the next line as many times as I want. I don't know if it's a bug or if it's waiting for something else. I've tried just saying no, pressing enter, and then waiting. After about 4 hours I figured if it's not done by now there is no point in waiting more.
Does someone of you know why this happens and/or how I can fix this?

Thank you in adavnce

Can you switch to Runlevel 3, before you try to uninstall the Nvidia driver?

I did that using the telinit command as the wiki suggests. It 'deactivated' the gui (sorry don't really know how to describe what happened). I ended on a black screen with only the terminal. I then did the same commands as before, and had the same problem. After typing No, it didn't do anything, in exactly the same way as before.