The Wii is a console created by Nintendo in 2006. It is one of the top five best-selling game consoles in history, and it shares many traits in its file system to Nintendo's previous console, the GameCube.
The Wii uses DVD-based technology, which generally would mean that files are visible from a disk through any standard ISO viewer or by inserting the DVD into your computer's disk drive. However, Nintendo specifically designed their disk drives to read files in a unique manner, making the reading on Wii game's disks require a special piece of software. There are a number of tools available.
It's possible to read the files from a Wii ISO through the Wii/GameCube emulator, Dolphin. If there isn't a way to decrypt your Wii Game that you're aware of, you might want to use Texture Dumping with this.
A tool that can decrypt most, if not all, LZ compressed Wii files. This is a command line tool, but it can be easy to use for newbies.
A GUI tool that can decrypt some Wii files. Today, you might want to only consider using this for WAD files (Downloadable Content and such) since it only decodes one file at a time.
Wiimms ISO Tools
A collection of tools to decrypt ISO, WBFS, WDF, WIA, and CISO files and rebuild them as well. This is a command line tool, but it can be easy to use for newbies.
Wiimms SZS Tools
A collection of tools to decrypt SZS, U8, WBZ, WU8, PACK, BRRES, BREFF, BREFT, BMG, KCL, KMP, MDL, PAT, TEX, TPL, BTI, main.dol and StaticR.rel files. Most of these can be encoded back into the file format you were playing with, and you can also do things in batch. This is a command line tool, but it can be easy to use for newbies.
Common File Formats
A U8 archive which can store TPLs, BRLYTs, BRLANs, and BRFNTs.
For more details on this file format, please visit the BRRES page.
A standard container file for 3D models, textures, and animations.
A standard sound stream file used in several games. The BRSAR can be read in later versions of BrawlBox.
A standard movie file used in most games which have movies in them. This file format is also present in several GameCube games as well.
An image file used in most Wii Games.
The process is done the same way as done in GameCube.