This is a replacement for Nintendo Wi-Fi Connection. A now defunct service that allowed Nintendo Wii and Nintendo DS users to play online with people across the globe.
For this, you'll need:
1. An SD card
2. Auto Wiimmfi Patcher
1. Extract the .zip file into the apps folder on your SD card.
2. Insert the SD card in your Wii and launch the Homebrew Channel, then open Auto Wiimmfi Patcher.
3. Insert the disc you'd like to patch.
4. The game will start soon. Do this every time you'd like to play online.
For this part, you'll just need a Wii with the Internet channel (no HBC needed).
1. Insert the disc you'd like to patch.
2. Ensure your Wii is in 60Hz mode in your system settings.
3. Open the internet channel and go to http://chadsoft.co.uk/wiimmfi/. Add this page to your favorites by pressing the "Add Favorite" (star with a plus) button. Press the Reset button on your console.
4. Open the Internet Channel once again. Go to your favorites and click on "Wiimmfi".
This is for those who'd like to permanently patch their backups (ISO/WBFS/cISO and etc. files) on their USB loader.
What you will need is:
1. The backup file of the disc.
2. This patcher (for MKWii only) or This patcher (for AC:WW only) or This patcher (for all other games)
Steps:
1. Put the patcher (.bat for Windows users, .sh for Mac users) and the game backup inside a folder of your choice. Run the patcher with the backup.
2. Once it's done, get the patched file inside "wiimmfi-images" (might be in the folder before it).
For this, you will need:
1. A SD Card with the WiiWare title (in .wad format)
2. Auto WiiWare Patcher
3. Wii Mod Lite
Steps:
1. Extract the .zip file into a folder with the .wad file.
2. Run the script (.bat for Windows users, .sh for Mac users)
3. Install the newly generated .wad folder in the "wiiware-wads" folder on your SD card and install it on your Wii.
You can patch/play online in more ways found here.