http://www.nvidia.com/object/nforce_udp_winxp_5.10.html
or if that link doesn't work
http://nvidia.com
click "Download drivers"
then "platform/nforce drivers"
Then "nforce 1/2"
then "windows xp"
I am of course assuming you have windows xp
Its a board based on the nvidia nforce chipset so those drivers should have the network port driver in them.