Linux Mint 13
I added a NVidia GeForce 6200 video card and installed the drivers via the Additional Drivers (I think that's what it's called, I can't boot up Mint now to see) menu. It seemed to be working, other than the typical inability to access the xorg.conf file for writing changes to unless opening the program from the command line.
I couldn't find anywhere that explained how to restart the X server, as instructed (all the references are to lightdm and gdm, which are not present), so I rebooted. I was greeted with, "You do not appear to be using the NVIDIA X driver. Please edit your X configuration file (just run `nvidia-xconfig` as root), and restart the X server." Foolishly, I then tried following these instructions:
http://www.theloudons.org/blog/2012/09/ ... -x-server/
I ran "sudo apt-get –purge remove xserver-xorg-video-nouveau" having read through the supporting page for warnings and explanations, and all seemed okay. It didn't make sense to follow the next steps, as I figured I already had the NVidia drivers installed, just not being accessed because Nouveau is the default. So, I skipped ahead to restaring the computer, as that's the only method of restarting the X server I could find. Oops. Now I'm greeted by a blue screen that says there is no X server configured, and I can't boot. It gives me a couple pages of info, but I don't know if there's anything useful in there to look for.