If you have a PC with an Nvidia graphic card you have to install the correct driver in order to accelerate 2D and 3D experience. There is also a slight possibility not to be able to see the login screen when you boot your PC for first time.

Envy is an unofficial ATI and NVIDIA driver installer for Ubuntu. It will:

1. detect the model of your graphic card (only ATI and Nvidia cards are supported) and install the appropriate driver. However automatic detection can be overridden with the "Manual installation"
2. install the right driver for your card and all the required dependencies
3. configure the Xserver for you

The official home page of Envy is:

http://www.albertomilone.com/nvidia_scripts1.html

If you cannot see the login screen due to resolution incompatibility, press the Ctrl+Alt+F1 buttons at a time. Log in and type:

sudo apt-get install envyng-core

Then start the EnvyNG typing:

sudo envyng -t

-t parameter means EnvyNG will start in textual interface. Go through the wizard and install the recommended driver. Restart the PC.

Log in using the graphical interface and check if you install the best available driver - System/Administration/Hardware Drivers. If necessery, activate another driver. Enjoy!