ight8, if you're a newbie you might consider this advice from a fellow newbie. Divide your hard drive in half (except for the swap partition). Use one half for your active installation and use the other half for a backup partition of the active one. I use partition commander for this purpose. Now only when you have an active partition that represents a good knoppix install, copy the active to the backup.

Now when you goof, and you will, and you find yourself unable to undo the damage without taking a lot of linux courses, merely copy the backup partition to the active one and you're up and running again. This has saved me at least 50 times so far.