Wad !link! | Vwii

If you receive an error (e.g., -1022 or -1029), try re-installing or, if it’s a re-installation, try pressing to uninstall it first.

: Installing a WAD from a different region (e.g., a PAL WAD on an NTSC console) can cause system issues. vWii Specifics : Users must vwii wad

The honest answer is:

A WAD (often referred to as a "Wii Archive") is a file format used to package content for installation into the Wii’s system memory. If you receive an error (e