Hi ,
1] Please let us know which flavour of Linux are you using? because most of the linux flavours configure the driver automatically .except for realtek NIC card.
2] Check out the name of the NIC card in windows.you can probably check that by the driver name or in the Installation CD. i.e. if its realtek8139,realtek8168 etc.
3] when you know the driver name please send us so that we can send you the Driver download and Installation instructions.
Regards,
Vishal Vinchankar