What steps did you actually take to install the wireless driver - using
ndiswrapper? That should be the way to go with that chipset (if you're sure that's the chipset in your laptop). I've never tried Knoppix with that chipset so don't know if it's supported straight off the CD live, but I guess since it's not activated by default
Maybe let us know what steps you took and what problems you're encountering. The ndiswrapper wiki is a good resource for getting things up and running. As a shot in the dark, a common problem is not having the appropriate kernel sources available when compiling ndiswrapper and thus your wireless driver cannot be installed.