Instructions
Open the front panel on your Nintendo Wii.
Insert your SD card into the slot inside the front panel on the console. The SD card's label should be facing upward and the small metal pins on one side of the card should be pointing toward the console, not away from it.
Turn on your Nintendo Wii.
Select the "SD Card" menu option using your Wii-mote to access the SD card loader on the 4.2 version of the Wii firmware. This will display the contents of the SD card on screen.