Try the following:
1) Completely power down your system by pressing the power button for 10
seconds. If that doesn't work, unplug the AC Adapter from the Wii for a
moment, then plug it back in.
2) Make sure your Wii console has the most current Wii system menu. Download the latest update, and then test your Wii console to determine if the problem has been resolved.
This is done by:
- Make sure your Wii console is successfully connected online.
- Access the Wii System Settings.
- Click on the blue arrow twice to reach the Wii System Settings
3 menu options.
- Select "Wii System Update" and press the A Button.
- Select "Yes," and read any messaging regarding obtaining the update. If you agree to the messaging, select "I Accept."
- The Wii console will now search for the latest Wii System Update.
- If an update is available, it will be downloaded and installed automatically.
I hope this can help you - Source: Nintendo Website.
* If this solution helped you, please accept it