This looks like another member's plight. The Vista Ultimate is usually found on machines that don't have the stock OS installed. Try drivers. But first.
This issue also occurs when Norton and other tools expire. I can't explain why they do that!
Toshiba Satellite A205 - laptop
Windows Vista Ultimate
Intel(R) Wireless WiFi Link 4965AGN
I set up my Belkin-N wireless router through the Toshiba mentioned above. I successfully connected an additional laptop (new Dell) to the network and it works fine. However, when I unplug the Ethernet cable and try to connect wirelessly on the Toshiba, it says I have "limited connectivity" and am unable to get on the Internet. I rebooted after set up, but it still won't work.
I've fiddled around a little bit, but I am at a loss. Help?