Knoppix is a brilliantly clever and astoundingly useful product. It runs Linux completely from CD. There is no need to install. It bypasses all the software already installed on your PC or laptop. It automatically detects the hardware in your computer, such as video card, sound card, networking, the lot (subject to suitable hardware). When you've finished using Knoppix, simply restart. Your computer will return to your regular system, and it will behave as if nothing has happened. Knoppix is Free Software and open source under the terms of the GNU General Public Licence (GPL).