If you wish to have more than one PC connected then you must do what we call Multihoming. A Multihomed system requires the computer to actually be a part of TWO Networks. Your home/Office network and an external Network (ie Roadrunner). To make a PC reside on multiple networks requires a Network card (NIC Network Interface Card) for each network you wish to participate in.

The simplest way around this is simply to pay the additional $10 a month for another RR IP addy. HOWEVER you will STILL not be able to have direct network connections with the other PC at your home. If you wished to have BOTH PC talk to each other Via LAN and ALSO have RR connectivety with both there are TWO ways to accomplish this.

1.) Install TWO NICs in each machine Pay for an additonal RR IP set one NIC in each machine for DHCP for the RR and set the other NIC in each machine with a specific hard IP addy on the same subnet (I know it sounds tricky but its not). Then both machines will see RR and each other.

2.) Install Windows NT Server on one machine or get a older PC you can get for cheap. Connect it directly to RR with one NIC and add another NIC for your home LAN. Setup Proxy services on the NT machine (This CAN be tricky for a novice). Then the NT server is the only machine actually on the Internet and you can add as many machines to the other side of the server as you wish. The NT server actually acts like a Firewall folks wishing to attack your connection actually hit the server and not your machine directly. Its safe its fairly fast (With a stout enough NT server) and its relatively cheap (If you have a spare PC and a copy of NT Server).

I am sorry there isnt a simple Plug this in nd turn this to setting B type answer for you.

Robert
(Former Senior Engineer for a Telecom) lol