Looks like something is detected. eth0 is one or other of your network adapters. My guess is it is the Realtek 8139. Knoppix has much more problems with wireless, and it does have the driver module for the 8139. So if you can, disable the wireless first and try fixing the Realtek.

From your screen shot, your eth0 is not "UP". You need to bring it up. Open a root shell and type "ifconfig eth0 up". When done, type ifconfig -a again. Your should now see a line under eth0 which says "UP BROADCAST MULTICAST etc...."

If the card is now "UP", try to configure it using the Knoppix menu -> Network/Internet -> Network Card Configuration.