backtrack 5

http://www.backtrack-linux.org/downloads/

• 32 bit version : http://www.backtrack-linux.org/ajax/download_redirect.php?id=BT5R3-KDE-32.iso
• 64 bit version : http://www.backtrack-linux.org/ajax/download_redirect.php?id=BT5R3-KDE-64.iso

for the live install you will need a USB stick with at least 4GB space.
for an easy liveinstall via unetbootin follow the live install instructions.

howto install a system with full diskencryption can be found here : bt5r3_hd_install