I have a Windows 7 laptop connected via a WRT54G2 wireless router to an XP SP3 desktop. Both the laptop and desktop can see shared resources and both can connected to the internet.
In the Laptop's Network and Sharing Center, however, things are not correct. The Laptop has two connections to the router, lan and wireless. The lan's connection appears OK, but I cannot generate a map. I get "Windows cannot discover any computer or device." The wireless network is public. I don't know why and I don't know how to change it. Also, when I try to create a new network connection, the laptop sees only a WRT160N router (which I don't have; perhaps I did a while ago, when the laptop ran Vista). No place to add a new one.
I have Cisco's Network Magic and it can correct see everything, including the right router.