Problems cable connecting Vista to XP network

I need help connecting a Vista desktop to an existing XP home network.

I am very familiar (up until now anyway) with windows networking, having worked all the way up from Windows 95. My present setup is as follows:

ISP service from Comcast into a modem. From there into a Linksys (Vonage) wireless router. I have two XP machines and a network printer on the network (cable connected) that are fine. I also have both an XP and a Vista laptop that I can connect via the wireless router. I do some limited PC configuration for my job and have always been able to plug in the cable and connect.

I just purchased a new HP Pavilion pd150t with Vista and in no way can I make it connect to the internet. Occasionally it will see the network printer but that's it. I also cannot see the new Vista machine from the existing XP's. Workgroup names are identical.

When trying to set up an Internet connection instead of using the default one, it wants my ISP username and password. I never had one.

 

Resolved

 

Even though I had the NIC set for automatic addressing, when I do an ipconfig /all, it returned an IP address that made no sense. My router gateway is 192.168.15.1 so I set the PC with a static IP of 192.168.15.125 and it worked. Once since that I lost the connection and the fix seemed to be to unplug the cable from the router and re-plug it.
It's working, but I'm still not convinced that the router is not the problem. It is a D-link/Vonage router.