Networking RCM advice needed


I could use some advice/help. I have a RCM, WBR-1310 D-Link router, laptop (XP), and a desktop PC (XP). When I run a sample HTTP program such as FORM1.C I am able to connect to the ISP address that the Rabbit is on using my desktop computer but I can’t with my laptop. I know that I probably need to adjust the network settings, but should this be done in Windows or the router. I have tried some different things but haven’t had any luck yet. Also I would like to eventually be able to access the Rabbit from beyond my own LAN using the internet. What would be the best, (ie safest, most reliable), method of doing this.