I see that is a wireless B router. I think the Wii can only run on Wireless G, but I may be wrong.
First. Do any other devices currently work with the router? (ie: Computer, PSP?)
Second. How far away is the Wii from the router? You probably dont want to go more than 150 feet with that particular router. Also, how many walls are between your Wii and the router?
Third. Have you been into the set up configuration in the Wii menu to establish a wireless connection. You may have to manually select the SSID, WEP, IP, etc.
Is all of this working correctly?