Connecting a laptop with Vista to an access point

My roommate has a laptop with Vista on it. I tried setting up a
wireless connection to my router but it wouldn't work. I would get a
message saying that it has "limited connectivity" with an explanation
saying that it is set-up but not connecting to the internet.
I have a WPA2 network set up and my router is a Belkin router. The way
I went about connecting for my roommate the first time I followed
instructions to configure the network with the WPA key and all. Then
when I try connecting to the network it says something to the effect
that the laptop is connected to the network but cannot access the
internet (I don't remember the exact error message).
How do I get this laptop to connect automatically?

-nish