Just backup your corrupted Nand with bootmii and create a new "fresh" nand with Giantpune's tool Ohneschwanzenegger. (Part of Wiiqt)
http://wiibrew.org/w...eschwanzenegger (Older version)
DLLs for Windows: http://www.mediafire...ow9bg9wsto5ak1w (Old)
If you want to compile it from the source...