Macbook pro can't connect to internet

Just got a macbook from a friend to fix something(first time using it). I can't establish a connection with it. I own a modem and got two ethernet cables, one goes into my win7 machine which works fine, and the other goes into the mac. The mac finds the lan connection correctly and displays the ip/submask/router address. Created a PPPoE connection, set the username / password but it can't connect to it, what am I doing wrong? It tries to connect for ~30 seconds and then says. "Couldn't find a PPPoE server for the appropriate service".