BackTrack Linux is now known as Kali Linux. You may read all Kali Linux articles and tutorial at http://linuxbsdos.com/category/kali-linux.

BackTrack 5 is a Linux distribution designed for penetration testers and other security professionals, or those who want to mess with all the best security and penetration testing applications the free software community has to offer.

BackTrack 5 R2 is the latest edition, officially released March 1 (2012). You have the option of downloading a GNOME 2 or KDE ISO installation image for 32- or 64-bit architectures. I have already written several articles using a 32-bit installation image of the KDE edition. Because the installers of the GNOME and KDE editions are slightly different, this article shows how to install the GNOME edition standalone. A future article will show to dual-boot it with Windows 7.

So, to start, download a suitable image from here. Burn it to a CD and boot the computer from it. The boot menu is shown here. By default, it should boot into a live desktop at the command line.
BackTrack 5 R2 GNOME Boot

To boot into a graphical desktop, type startx, then press the Enter or Return key on the keyboard.
BackTrack 5 R2 GNOME Startx

Once in the graphical live desktop, click on the Install BackTrack icon on the desktop. This edition is based on Ubuntu 10.04 LTS, so if you still remember what the installer of that edition of Ubuntu looks like, you should be in familiar territory. The installation process is a simple, point-and-click, 7-step process. The fourth step, shown here, is the disk partitioning step. If your objective is to install it standalone on the computer, select the option shown in the image, and click Forward.
BackTrack 5 R2 GNOME Installer

By default, the boot loader is installed in the Master Boot Record (MBR) of the hard drive. Just be sure to verify that.
BackTrack 5 R2 GNOME GRUB

After the installation has completed successfully, rebooting will drop you to a command line login prompt. Type the username root, the type toor for the password. Note the case. You will be logged in to a command line environment. Type startx to start the graphical desktop. Once you are logged in, be sure to change the default password. To do that, launch a shell terminal and type sudo password. Then type you new password, twice.
BackTrack 5 R2 GNOME Root Login

This just shows what the desktop looks like. Happy hacking.
BackTrack 5 R2 GNOME Desktop