Ok. Have you run netcardconfig yet? Try that as it's the easiest way to set up an ethernet card.

If you run it and it says no ethernet card detected, then we've got to check out your card a little more carefully. If that happens, you need to post the output of the following two commands:

dmesg (this will display all the information that is shown during bootup - including hardware detection messages)

lspci (this will display which pci devices are attached to your motherboard and detected by knoppix)

If you want to export the out of these commands to text files then do this.

dmesg > dmesg.txt
lspci > lspci.txt

So try netcardconfig out first and then if you need to do so, investigate things as I have indicated above. Post back the info if netcardconfig doesn't work.