I just tried the DVD version of LiveCD Knoppix linux and now one of my ethernet cards doesn't work

I have a DFI Lanparty expert mobo and when linux was booting up it seemed to recognise both LAN ports (one is a marvell yukon, the other being an Nvidea) but then wouldn't allow me to connect to the net. I played around with linux, rebooted into windows, everything seemed to be OK but.....my Marvell Yukon card seems to be disabled. Could a LiveCD version of the OS tell my ethernet card to powerdown and stay off? The BIOS recognises the card as does windows hardware profile but now no connection or flashing lights.

grrrrr so much for trying linux

Please help resort my confidence in linux, any help?????