Based on this link nvidia-361 is the driver for GTX 950M(same as in my other laptop).
Ctrl+Alt+T and then login to the tty
First uninstall the currently installed NVIDIA drivers. Boot the computer, when the GRUB menu appears ...
Highlight the Ubuntu menu entry and press the E key. Add nouveau.modeset=0
to the end of the linux line. Press F10 to boot the Ubuntu operating system.
When the login screen appears press Ctrl+Alt+F1. Enter your user name and the password, then execute :
sudo apt-get purge nvidia*
sudo reboot
Now install the latest official stable NVIDIA drivers. Boot the computer, when the GRUB menu appears ...
Highlight the Ubuntu menu entry and press the E key. Add nouveau.modeset=0
to the end of the linux line. Press F10 to boot the Ubuntu operating system.
When the login screen appears press Ctrl+Alt+F1. Enter your user name and the password, then execute :
sudo add-apt-repository ppa:graphics-drivers/ppa
sudo apt-get update
sudo apt-get install nvidia-361
sudo reboot
Note : Maybe it is explicitly necessary to select the NVIDIA adapter in BIOS. When you want to use drivers 361, adding the PPA is not necessary. In this case the terminal commands you have to perform are these :
sudo apt-get update
sudo apt-get install nvidia-361
sudo reboot
In case you have installed the nvidia driver from their site then uninstall it as per that instructions.Uninstall that driver by running, as root, sh ./NVIDIA-Linux-x86_64-3
Similar kind of solution i have provided in this thread