LetterBomb is an exploit capable of launching homebrew from the System Menu version 4.3. It was created by Tueidj to replace Bannerbomb, which does not work on System Menu 4.3.
The exploit works by using a malformed Wii message to crash the Wii Message Board and run code to load the boot.elf placed in the root of the SD card. It can be used to install the Homebrew Channel and BootMii via the HackMii Installer.
LetterBomb (The HackMii Installer is included with LetterBomb; leave the box checked that says "Bundle the HackMii Installer for me!")
See the guide below for how to download the exploit.
What you need:
- SD card (or SDHC card) formatted as FAT(16) or FAT32. Most, if not all, SD cards are already in this format so you can skip this step unless your card is not detected by your Wii.
- SD card reader for PC or a PC with one built-in. (Cameras or other devices can work)
- Your Wii's MAC Address (See #1 on the Guide below)
- LetterBomb message data on your SD Card. (Download above)
- Some homebrew to load (In this case, the HackMii Installer)
- System Menu 4.3
- You must have at least one message on your Wii before trying to run the exploit. If you don't then simply create a memo on the Wii Message Board.
- Find your Wii's WiFi MAC Address. Go to Wii Options --> Wii Settings --> (Go to page 2) --> Internet --> Console Information. This is needed because the Wii will only accept messages addressed to its specific MAC address.
- Enter the MAC address on the LetterBomb site and select the correct region of your Wii. Enter the captcha and click either of the buttons.
- If your SD card has a "private" folder, rename it temporarily, e.g. to "privateold".
- Copy the LetterBomb "private" folder to the root of your SD card.
- Take the HackMii Installer "boot.elf" and copy it to the root directory of your SD card. (Root means not in any folders, just on the SD card.)
- Put your SD card in your Wii and turn it on.
- Go to the Wii Message Board and wait a little bit for the messages to load. LetterBomb should be wherever "today" is but depending on your time zone it can be on "yesterday" or "two days ago".
- Click the letter and the homebrew on your SD card will load. Enjoy!
Finding the MAC Address
Some Wii's have MAC addresses that don't match with Nintendo's list of MAC addresses (for example 00:1A:E4:xx:xx:xx or 0e:0c:7f:xx:xx:xx will not work). The workaround for these Wii's is to use Wilbrand rather than Letterbomb.