Instructions
Test your D-Link network using your computer. If you can access the Internet on a computer connected to that router, your network is functioning fine.
Power on the Wii console, and bring up the Home menu.
Click the "Wii" button in the lower-left corner of the screen, select "Settings" and scroll to "Network settings."
Select "Wireless connection," and click "Search for Access Point." Select the D-Link router from the list of available networks.
Input your D-link network password when prompted. Type in the password using the on-screen keyboard, and click "Enter." If you don't have a network password, you can skip this step. If you don't know the password, you can look it up on your computer. Open a browser window on your computer, type in "http://192.168.0.1" You will be prompted for a username and password, which defaults to "admin" and "password." The password is located under "Wireless" on the Home tab.
Test the connection when prompted. If the test is successful, you are done. If unsuccessful, find your D-Link router model on the list located under Resource to see if there are additional notes from Nintendo for that model.