Place your WBFS files in a specific folder structure. At the root of your USB drive, create a folder named wbfs . Inside this folder, each game should be in its own subfolder with the following naming convention:
A game like New Super Mario Bros. Wii shrinks from a 4.37 GB ISO down to a mere 350 MB WBFS file. wii roms wbfs europe link
Ensure your USB drive is formatted to FAT32 (max 4 GB file size) before using it with the Wii. For large libraries, partition the drive into multiple 32 GB volumes. Place your WBFS files in a specific folder structure