Ok lets try this again lol.
Things to check:
1. There should be a installer log created on the SD card after running the Hackmii installer. Copy and paste that here
2. Make sure the SD card is not write protected. (Put it into computer, and try to delete a file off it, if it allows it, its not write protected)
3. Format the SD card. (Use this program,
https://www.sdcard.o..._3/eula_windows)
4. Load MMM through Letterbomb (
http://mmm4wii.poste...od-manager-v134)
5. Run the option "Install and Patch IOS36" (You are going to need wifi)
6. Select the option "Load Another IOS" and select "IOS36"
7. Using the IOS Manager; Delete IOS30, IOS34, IOS20 and IOS10. Reinstall the latest version of all these IOS files besides IOS34. Install IOS34-v3348
8. Also in MMM use the option "Removed Stubbed IOSs"
9. Redownload the Hackmii installer and try running the Letterbomb exploit and installing again.
Edit. Rofl just read the post above me.
After you get this sorted out I suggest looking into a guide to "virginize your wii" (Get all your IOS files re installed.)