Can't write to an SD Card
Wii allows you to save game progress and other data right to the console's internal memory. An SD card is not required. However, we understand that players may want to use an SD Card to back up their data.
To write to an SD Card, the Wii console requires a downloaded update. To download updates you will need to connect your Wii to the internet. For information on how, please click here.
Please note, without the update, you can still transfer data off an SD card for use in the Photo Channel. This allows you to view your images, movies, and listen to AAC (.m4a) files.
For more information about the audio files in the Photo Channel, click here.
If you wish to use an SD Card as a storage device, but are unable to connect your Wii console online or have no plans to do so, please contact Nintendo Consumer Service to discuss options available to you in this regard.