The most reliable way to secure your Wii is to create your own backup using BootMii .
: Sharing NAND backups is considered illegal as they contain copyrighted Nintendo system software. Additionally, untrusted files could contain malicious data that might damage your system. How to Properly Create a NAND Backup Wii Nand Backup Files Download
The NAND flash memory in your Wii holds the operating system, system menu, channels, save data, and critical console-specific encryption keys. Protection Against Bricks The most reliable way to secure your Wii
If your Wii is already homebrewed, you can create a 1:1 copy of your system memory in minutes. Tool Needed : BootMii (installed via the HackMii Installer). : An SD card with at least 600MB of free space. The Process (either via the Homebrew Channel or at system boot). How to Properly Create a NAND Backup The