Try this link the answer your looking for is already here on CNET
Im sure it will help you get your PS2 connectied.
I purchased the PlayStation 2's Network Adaptor and an Ethernet Cable. My computer came with an Intel PRO/100VE card.
I tried to get the PlayStation to connect through the connection from the PS2's Network Adaptor to the Intel PRO/100VE card but it can't make a connection and the card lists that a "Network cable is unplugged."
I know little about computer hardware and even less about networking, anyone have any ideas?