Things You'll Need
Instructions
Insert your Nintendo DSi's SD card into the SD card slot on the side of the DSi if its SD card already has the game loaded. The SD card slot is concealed with a thin square plastic piece that you can pull downward to reveal the slot. Slide the DSi's SD card in.
Power on the Nintendo DSi and look at the screen. You can now select the game from your menu.
Transfer the game off another SD card onto the SD card you use with your Nintendo DSi, if necessary. Begin by inserting the non-DSi SD card into the SD card slot on your computer.
Open Windows Explorer on your PC or the Finder on your Mac. This will allow you to access the contents of the SD card. You will see a drive listing corresponding to the SD card drive on the side of the Explorer or Finder box that appears.
Use your mouse to highlight the desired game data and drag it to the desktop area of your computer--or the alternate area of your computer you wish to store it on.
Remove the SD card. Insert your Nintendo DSi SD card in its place.
Use Windows Explorer or your Finder on your computer to access the DSi SD card in the same manner as you did the other card. Drag the game data from your desktop or other computer location to the DSi SD card.
Remove the DSi SD card and insert it into your Nintendo DSi to access the game.