Wii shop channel without updating 4 1
Either of these firmwares is safe, so feel free to choose either one.
Please note that these deletion measures will not affect Wii consoles that contain only normal save files.
PART 3 is optional and allows you to block future disc and network updates that are not yet released at the time of writing of this tutorial.
For more information about upgrading, see the Upgrade FAQ.
This is not needed for any games, provided you used the d2x instructions in this tutorial already, so the only protection is from updates that are not yet released.
The procedure to perform this can be found at the Avoid Disc Updates page.
Note that a power outage might brick your Wii, so do not perform these steps in a storm or other situation where power outages are likely to occur. There are then several methods you can use to upgrade to firmware version 4.2 or 4.3 (in PART 2).