Wireless support in Knoppix is not great. Wireless support in Linux isn't perfect either, many manufacturers don't produce Linux drivers or release specs on the chips needed by independent driver writers. This is an on going problem. See the wireless networking section of the wiki for more details.

There are some wifi drivers in Knoppix. Unfortunately, I have not been able to get the one wifi card that I have that Knoppix does recognize and used to work in version 4.02 to work in any 5.x version, so I'm hardly the best one to give advice here. But if you tell people what make and model of card and/or chipset that you have someone may be able to help you. Be as specific as you can, don't just say you have a Dlink card, for example, give the model number and even the hardware version number. Card manufacturers often sell cards with differennt chipsets that need completely different drivers under the same model number and change only a hardware version number.

You might be able to use Windows drivers with "wrapper" software. Doesn't work with all drivers (never worked for me), but it has worked for some.

Quite frankly, I would suggest that hardwiring your computer may be your best bet. Or using a version of Linux with better wifi support, but it's certainly worth determining what the support status of your particular hardware is before you change from Knoppix.

As this is a networking quetion, it will be moved to the networking forum, where you may get better responses.