kmaki

I have cable modem connected to Win XP SP2 via router. I am trying to connect a second PC with Windows 2000 so that it can access internet and some files. I have cable from Win2k PC to router and thought it would have immediate access ... but it is unable to access internet. I have created "Home" workgroup on both but neither PC is recognizing the other. What have I overlooked? I apologize if my quesiton is too basic for this forum. Thank you.