I have something similar - USBLOader detects my Hard disk, detects the gamecube games on that usb hard disk but stubbornly refuses to see the WII games :)
OK.. First of all I did a syscheck on the wii, copied it over to SD card, stuck the SD in my laptop and dragged it onto an open ModMII window. It failed to download the all the IOS's so then picked the remaining IOS's as my message above.
Still a noob myself - but seemed the right thing to do.
I got it working in Modmii, by typing I Agree, then hitting 1, then adding each of the 'Fakesigned' IOS files, along with any others I missed. Only way I could get it to work. Hope that helps.
Ridiculously long term lurker, first time post..
Fired up the wii after a hiatus of 2 years for the kids. Just fired up ModMii to update and I'm getting some failures on MD5 checksums.. Anyone else had the same?
OS is Windows 10 Anniversary Edition - and tried with Firewall on and off...