Huge Breakthrough here! (for me !)
For all those people That get Reset Friend Codes and similar status values, such as Incorrect WFC ID On a restart of the emu : Firmware is randomized if using the internal Firmware, using a successful external Firmware (saving that is) will keep the same "profile" even if you turn off the emulator or computer.
For all those people That can't save Custom Firmware Settings due to Config Save : Failed , Even having run as Admin : I believe this is a Windows 7 issue for some people, I'm not sure why it happens... well I reformatted PC yesterday Win 7 Clean, same error...
... BUT, I also installed Windows XP before the clean Windows 7, And as I had tested on my brothers computer which had XP and it worked PERFECTLY, I expected the coming results : PERFECT.
For all those with 20140, 52000, 52100, 52200 errors Just do the following, it just can't be said enough times :
Disable all firewalls.
Install WinPCap as Admin
Download Slytherx's version of the emulator (or whatever his awesome name was)
Get the firmware.dfc file from John3
Get the BIOS files and a firmware file.
Setup wifi to the Infrastructure ethernet interface in emulators wifi settings.
Set up your custom firmware as the tutorial says (if your config fails to save even running as Admin on Win 7, then do as i did, get Windows XP (a REAL HASSLE though~)) and close the emulator.
Make sure to Run WinPCap executable (rpcapd.exe) as ADMIN before starting the emulator. (well I'm not sure how it works (?) BUT IT has worked for me <,<)