Well, it booted into maintenance mode, so I figured jbc007's suggestion was correct and I tried formatting my system memory. It didn't fix the problem. Now it: - boots to the "Press A" screen - after a little bit, goes back to the "System files are corrupted" message - can't load HBC from bootmii, but I can get to the hackmii installer (through the bootmini.elf file and theby chardish - FixMii
So, my Wii is somewhat bricked. I have a very old Wii (bought it the week of launch, but not the day of launch.) Initially installed HBC via Twilight Hack, used HBC to keep my homebrew fairly current. Didn't update via Nintendo at all. Last month I bought New Super Mario Bros. Wii, and stupidly told it that I wanted to install the update from the disc. (I don't know what I was thby chardish - FixMii