Choose the button (first one on the left) to save nand.bin to your SD card.
If you already have a NAND file and need to extract or modify it, these tools are widely used in the homebrew community: MarioCube Repository Startup Disc NAND + Extracted nand wii download link
This is the safest and most legal method. You will need: Choose the button (first one on the left) to save nand
Reviews of "NAND Wii download links"—typically referring to tools like NUS Downloader or WiiUDownloader —highlight their utility for preserving console functionality, though they carry inherent risks if used directly on hardware. and system files.
A NAND backup ( nand.bin ) contains your console's unique encryption keys, serial number, and system files.