NAND Flash Memory is the built in memory of the Wii console. It houses save data, downloaded channels, and the Wii Menu. Some games may require files only found in a full NAND dump to work correctly. The easiest way to do that is with BootMii. For alternate methods, see the forum thread.
To dump NAND with BootMii, you'll need:
Access BootMii through the Homebrew Channel. Use a GameCube Controller or the Power and Reset buttons to navigate through the BootMii menus, as detailed here. Select Options (gears icon) on the far right. Select Backup NAND (Green arrow from chip to the SD card), and wait until it completes. Once completed, remove the SD card and put it into your system. You should see a file named nand.bin on the SD Card. If you do, your NAND has been backed up.
Select Tools > Import BootMii NAND Backup. Dolphin will decrypt and unpack the NAND. Device credentials and system files required for network services emulation will also be extracted automatically.
If you are unable to import your NAND automatically or simply wish to browse the contents without installing to Dolphin, then here are steps to manually extract your NAND.
dd if=keys.bin of=aes-iv bs=1 skip=360 count=16
dd if=keys.bin of=nand-key bs=1 skip=344 count=16
openssl enc -d -aes-128-cbc -in nand.bin -out nand-decrypted.bin -K $(hexdump -v -e '/1 "%02X"' < nand-key) -iv $(hexdump -v -e '/1 "%02X"' < aes-iv) -nopad
Use NAND Tools to extract the files from nand.bin. This package includes the following:
Place the files nand.bin and keys.bin that you've acquired from the last section into the working directory, open cmd.lnk (A shortcut file that will open a command prompt in the current directory), and then type the following commands into the prompt:
|Extracts the AES key from your nand.bin into a file called nand-key.bin.
|NAND-bin2raw.exe nand.bin nand_dec.bin
|Performs decryption on nand.bin, and writes the output to a file named nand_dec.bin
|zestig.exe nand-key.bin nand_dec.bin nand
|Extracts everything from nand_dec.bin and places it into a new folder called "nand".
|Closes your command prompt.
After this is finished, a new folder \nand\ should be created in the working directory.