I can see the question comming, so here's the real answer.

Knoppix 3.8.1 and up (3.9 is current as of this writing) does not work properly with Virtual PC. Knoppix incorrectly detects the network adapter as a D-Link adapter, and installs the wrong networking drivers causing the virtual machine to crash. If you search for the solution to this problem you will find: “If networking crashes you machine, don’t use networking then,” which is just not a good solution. The correct solution is as follows.

1.Boot Knoppix with the nodhcp cheatcode. This prevents Knoppix from trying to access the network adapter and crashing before you have a chance to fix things
2. As root (of course), execute the following commands:
3. modprobe –r de4x5
4. modprobe tulip
5. ifconfig eth0 up
6. pump –i eth0
7. Enjoy network access.