Knoppix is a bootable CD. Although it's certainly not unique in that, the organization and content of a Knoppix CD are distinctive. Consider a few scenarios. Suppose you're an instructor. You meet your students in a training room, with only half an hour to check out all the hardware and prepare configurations for them. The result is inevitable: halfway through class, some of your demonstrations won't work, because at least a few of the student machines will have inconsistent Service Pack installations, or hardware that's never been exercised, or an environment customized by a subtle neurotic.