The cIOS (custom IOS) is a custom piece of software that is used by some applications that work with unofficial content.
By installing it, you can for example use Backup Loaders and install unofficial channels to your Wii menu.
Every cIOS uses an official IOS by Nintendo as its base.
This guide uses an updated method to bypass the old IOS236 installation ("trucha bug restoring") steps.
The old steps are still available here, but should only be used if the newer guide doesn't work.
Note: While a cIOS is installed by most people for Backup Loaders, it is also needed by a handful of other applications to work.
There are many applications however that don't need a cIOS.
Most of the Homebrew Applications on Wiibrew only need the Homebrew Channel.
Offline NUS Downloads
If you have no WiFi access on your wii, follow these additional steps first.
Else skip to the guide below.
These steps don't apply to the WiiU, since it uses another method to get the WADs.
1. Start up NUS Downloader. If you don't have it, you can grab it on its page (or direct download link)
2. Make sure that "Pack WAD" is enabled.
3. Using the database, navigate to the following files and press start NUS Download for each one:
4. Open the NUS Downloader directory (the folder where you placed NUS Downloader, you can use extras -> open NUSD directory to open it easily).
You will see a folder named titles. You will find two new folders in this directory:
In each folder, there is another folder for the version you just downloaded. Open this version folder and find a WAD file:
Copy both WAD files to the root of the SD card.
1. Start off by downloading the cIOS Installer (If you are softmodding a WiiU, use this one instead)
Inside the zip will be a d2x-cios-installer folder (inside the hbc folder for the WiiU version). Copy this folder to the Apps folder on your SD card.
Your SD card should look like this:
2. Updating the installer with the newest version
Go to the cIOSD2X Website and download the newest version: http://code.google.com/p/d2x-cios/downloads/list
You can either choose for the beta version (which we recommend) or the latest final one (which may be more stable, but lacks features)
Extract the zip file to the d2x-cios-installer folder on the SD card.
Your SD should now look like this (verify):
3. Insert you SD card into the Wii.
Start it up and go to the Homebrew Channel.
Now locate the cIOS D2X Installer and run it.
4. Wait for the app to load. Read the text on the welcome screen (if it interests you) and press A to continue.
5. Time to install the cIOSs
You are now on the main configuration screen. A lot of options will be available here.
You are now ready to install, so press A to continue. You will land on an overview with the available cIOS slots.
The slot you just selected should be blinking. Several other slots may be highlighted in red.
Press A to start the installation.
Wait for the progress to complete. It may take a while, especially for the online installation.
Once it finishes, you will land on another IOS overview screen.
Your freshly installed cIOS should be highlighted in a green color.
Press the A button to go back to the configuration screen.
Next, you want to configure the second cIOS. This time, use base 57, and choose a different slot (250 in this tutorial).
Again, press A to install it and wait for the process to finish.
Once everything is installed, press B to exit the application.
You are now able to run any backup loader you want! Enjoy!
We recommend you to use a USB loader.
USB loaders do not require DVD burning and have much better speeds and interfaces.