Things You'll Need
Instructions
Turn on your computer and insert the SD card into the card reader on your computer. Once the computer has read the SD card, it will prompt you to open the folder of the SD card, then click "OK."
Right-click on the ISO file that you wish to transfer and select "Copy." Right-click in the folder view of the SD card and select "Paste." Wait for the file to transfer completely.
Remove the SD card from the computer. There is usually an "eject" or "safely remove hardware" option in the menu of the SD card screen that is open. These options should be used versus just pulling the card out, because they help ensure the data will not be corrupted upon removal.
Insert the SD card into your Wii and turn it on. Navigate to the Home Brew Channel by pointing the Wiimote at it and pressing "A" to select it. Open up USBLoader from the channel by highlighting it and pressing "A." This will open up a folder view of the contents of the SD card. Select the ISO that you wish to transfer and press "A" to make it transfer. Once it finishes copying, you are done.