The autoboot discs probably don't work because you don't have the Trucha Bug (it's blocked at 3.3). You need to force your wii into the data screen and run bannerbomb, or the settings screen and format it (not the best option).
You can force the wii into the data screen by filling up the nand with saves and channels. Burn a whole lot of autoboot games to fill it up (ones that use a lot of save space or can install channels), or use a Guitar Hero and fill up the nand with free downloadable songs.
If that method is too tedious and you're feeling a bit brave, you could use WiiFit to force the Wii to the settings screen (by saying that the time is incorrect) and formatting. I wouldn't recommend this though, as you have a Korean wii and I'm not sure what a format does to it.