Installing BackTrack 4 Final couldn't be easier. I've expanded just a little on the simple installation instructions from BackTrack. Follow these simple instructions and you'll be using BackTrack 4 Final in no time. NOTE: These instructions assume you are going to use the entire disk on your computer for BackTrack.
First, boot the the BackTrack 4 Final DVD. Either allow it to start on its own or select your preferred screen size.
At the command line enter startx.
Double-click install.sh on the desktop.
Select your region/city for the correct timezone, click Forward. Select your keyboard layout, then Forward. Use the default disk partitioning option of Guided. Click Forward.
Click Install and watch it go.
The installation should only take a few minutes.
When it's done it will prompt you to remove your DVD and reboot. That's it. Now you're BackTracking.
NOTE: when your system starts your default username will be root, with the password of toor.
See How to Start Networking in BackTrack 4