I have a client with a domain and they have a few laptops running Vista Home, which of course wont join the domain. However, the laptops do connect to the wireless routers and lease a IP address via DHCP. I recently added a new wireless router as one of the laptops is used in a distant part of the plant and wasn't getting enough signal. This router is configured just like the one the laptop was connecting to except the SSID is different. When I try to connect Vista to it, it grabs a valid IP for about 30 seconds but then drops it and reverts to
Networking and Sharing Center shows the computer connected to the router, but displays Unknown Network to the right of that.

What's odd is that I have another machine, this one running XP Pro and a member of the domain, that is also using the new router but without any problems. This leads me to believe it's something with Vista Home.

The IP range for the network is with a subnet

This post i believed should be in the networking forum but anyway i will still see and reply to it. Can you explain your problem in more simpler words. Like you say the laptop got an IP address for 30 seconds and after that the IP address change to another one. Meaning different IP address. Second point you said that it show connected by it also said unknown network. Does the network sign have an exclamation mark on it. Have you change any settings before and try resetting your router. It might be a random error, try reset your modem, if the problem occurs. Something is wrong with the vista laptop. Good luck

P.S : We need more info. Thanks!