I have downloaded the iso image of Knoppix v 4.0.2 and burned it on CD .But when I intend to boot from the CD, after main screen which requires the return key to be pressed, I get the message;

Scanning for USB/Firewire devices...Done
Can't find Knoppix filesystem sorry. Dropping you to an (very limited) shell. Press reset button to quit.

What is the problem and how can be solved? Thank you.

**There are many like that in forum but really couldnt understand the case as a new user. Sorry for the new thread.