Wii Backup Manager
Wii Backup Manager (WBM) is a Windows program to help transfer Wii games to and from hard drives and SD cards.
It can also download game covers, list your games, identify what games are missing between devices, and more.

• You can use this program to manage/transfer your backup copies of Wii Games (.WBFS/.ISO/.CISO).
• It is very simple to use, but a detailed tutorial on using Wii Backup Manager can be found here.
• Wii Game Directory Structure:
  • Below is a single WBFS example, and a split WBFS example. A WBFS file needs to be split if it is over 4GB and your storage device is formatted as FAT32. During transfer operations WBM can automatically split games and set up the directory structure for you.
    
    💾 SD Card or USB Drive
    ┗ 📂wbfs
          ┣ 📂GameName [GameID]
          ┃ ┗ 📜GameID.wbfs (for non-split titles)
          ┗ 📂GameName [GameID]
               ┣ 📜GameID.wbfs
               ┗ 📜GameID.wbf1
    

GameCube Backup Manager
GameCube Backup Manager (GCBM) is a Windows program to help transfer GameCube games to and from hard drives and SD cards.
The interface is very similar to the popular Wii Backup Manager program making it easy to use.

• You can use this program to manage/transfer your backup copies of GameCube Games (.ISO/.CISO/.GCM and extracted FST format).
• More detailed usage information on GameCube Backup Manager can be found here.
• Gamecube (Nintendont) Game Directory Structure:
  • Below is a single disc game example, and 2-disc game example. Subdirectories are optional for 1-disc games in ISO/GCM and CISO format. During transfer operations GCBM can automatically and correctly set up the directory structure for you.
    
    💾 SD Card or USB Drive
    ┗ 📂games
          ┣ 📂GameName [GameID]
          ┃ ┗ 📜game.ciso (for single disc games)
          ┗ 📂GameName [GameID]
               ┣ 📜game.iso
               ┗ 📜disc2.iso
    

NKit Processing App
NKit is a Nintendo ToolKit that can Recover and Preserve Wii and GameCube disc images.

• Practically speaking you will only need this app if you encounter an "NKit.iso" or "NKit.gcz" game backup, which are not supported by WBM or GCBM.
  • Usually these files have NKit in their names, but if WBM or GCBM cannot handle a backup it may be an unlabelled NKit backup.
  
  
• How to use the NKit Processing App to convert NKit backups to ISO
  1. Drag and drop source file(s) onto the NKit Processing App window.
  2. Select "Convert to ISO" Mode.
  3. Click "Process".
  4. When finished, the converted game will be saved to: ..\NKit\Processed\Wii_MatchFail\
  • Click here for a short video tutorial.
  
  
• After converting from NKit to ISO, backups can be handled by WBM and GCBM like normal.

How to Backup Original Discs
Ripping original Wii discs cannot be done on a computer without one of the rare disc drives that are capable of doing so (most are LG branded).