ModMii uses cmd line patchios.exe + libwiisharp, but there are a lot of tools that can do that on windows or on your Wii.
@auriga1000, if u got this error using modmii, which i doubt, then its because u did not tell ModMii that your wii was a Korean region changed Wii when it really was and you also chose a 4.2 or 4.3 upgrade.
003 errors don't belong in this thread, good luck fixing it, but I have no experience in that area
@Rico, it could be your harddrive, maybe its partitioned oddly. Is it fat32? The new forwarder channel should be able to launch it off of either fat32 or ntfs, but the HBC can only read FAT32 (obviously u'd have to hit 1 to access the menu to change the settings to load of USB instead of SD)