When the software is run, the IOS that is hardcoded gets loaded by the Wii, which then loads the software itself.If that IOS does not exist on the Wii, in the case of disc-based software, it gets installed automatically (after the user is prompted).
and not to be confused with "i OS", the operating system of Apple's i Phones and i Pads), which run on a separate ARM architecture processor to other Wii software (nicknamed Starlet by the Wii homebrew community, as it is physically located inside the graphics chip, the ATI Hollywood, so it is a small part of Hollywood.).
Each Wii has its own unique 16-digit Wii Code for use with Wii's non-game features.
With Internet connection enabled users are able to access the established Nintendo Wi-Fi Connection service.
When a new update became available Nintendo sent a message to connected systems notifying them of the available update.
so that players who are not connected to the Internet can still update their system.