Things You'll Need
Instructions
Turn off you older Nintendo DSi device by pressing the "Power" button for three seconds. Insert the first SD card into the "SD Card" slot on the side of the device. Press the "Power" button to turn on the device. On the main menu located on the touch-screen, side-scroll to the "System Settings" icon on the touch-screen.
Tap the "System Settings" icon and then tap the "Data Management" button at the top of the next screen. From the "System Memory" tab, tap on the game data that you want to transfer to the new device. Tap the "Copy" button on the System Memory pop-up screen and then tap "Copy" on the next screen. Repeat this for each of the Nintendo DSiWare data that you'd like to copy.
Tap the "Back" button at the bottom of the touch-screen. Tap the "DSi Menu" button at the bottom of the next screen and then tap "Yes" on the next pop-up window. Your DSi will return to the main menu.
Press the "Power" button for three seconds to turn off the Nintendo DSi handheld device. Remove the SD card from the older DSi device and insert it into your PC. Double-click on the "Computer" icon on your PC's desktop and then double-click on the SD card drive.
Hold the "CTRL" button down and then press the "A" button on your keyboard. All of the files on the SD card will be selected. Hold the "CTRL" button down and then press the "C" button to copy all the files on the SD card. Navigate to your PC's desktop and hold the "CTRL" button down while pressing the "V" button. The files on the SD card are now pasted onto your PC's desktop.
Remove the SD card from the PC's SD card slot and insert the second SD card. Click on the "Computer" folder on your desktop and then double-click the new SD card drive. Right-click any white space within the SD card drive's folder and select "Paste." The files that were pasted onto your desktop will also paste into the new SD card's folder.
Remove the second SD card from the PC and insert it into the new DSi device. Make sure that the new DSi device is turned off while inserting the SD card.
Press the "Power" button on the new DSi device and side-scroll to the "System Settings" icon on the touch-screen. Tap the "Data Management" button and then tap the "SD Card" tab at the top of the screen.
Tap the DSiWare file and then tap the "Copy" button on the pop-up window that appears. Tap the "Copy" button on the following screen. The DSiWare files will save onto the System Memory of the new DSi.