Things You'll Need
Instructions
Power on the Nintendo DSi and select "System Settings," which is represented by the wrench icon on the home screen.
Tap the right arrow to access the third page of menu options, and click "Internet."
Choose the "Connection Settings" option.
Select "None" for "Connection 1." If "None" is not available, click "Clear Settings."
Click the "Search for an Access Point" button. The DSi will search for all wireless Internet networks within range and list them.
Select your wireless network from the list. Enter your WEP or WPA security key, if prompted. Then click "OK."
Click "Save Settings" and click "Yes." The DSi will run a connection test. If no connection is made, an error code will be displayed. Error code 51300 or 51099 indicate that you've entered an incorrect security key. Start the connection process again if no connection is made.