Things You'll Need
Instructions
Alright my friend, well the first step to playing any NES &SNES games is to first install the Homebrew Channel and the Homebrew Browser. Please visit the warnings below. If you have not done so, please visit the article titled, How to Install the Wii Homebrew Channel For Free on v4.0:
http://www.ehow.com/how_5355786_install-wii-homebrew-channel-v.html
You got the homebrew channel now, and the homebrew browser. You are set. Open up the homebrew channel and run the homebrew browser. Occasionally the browser needs updated, it might ask when it starts to load. Go ahead and update it if needed. It will take a minute.
So you have the browser open, good. Click on the emulators tab. Alright, now just browse down through the list. You are looking for a file named, Snes9x GX. That is the SNES emulator. Click it when you find it. In the next screen, click download. Wait for it to download and extract to your card. That's it. It's that simple, the SNES emulator is installed.
Now do the same for the NES emulator. It is named, FCE Ultra GX.
Now the wii homebrew browser has installed the emulators for you, but you still need games. Emulators play roms. So go get some NES and SNES roms. If you own the game (I know I have a whole slew of nes and snes games I still own) you may be in possession of and playing the rom for it. Go find it (where to get the roms is your job now, though I guarantee there are plenty of places to get them).
Once you have a rom to play, you need to put it somewhere where the emulator will find it. So turn off the wii, and take out your sd card with the emulators on them. On the root/home directory of the card should be a folder named, snes9x. Open this and you will find a folder named roms. Yep, you got it. This is where the SNES roms go. Put it in there. For the NES, you should have a folder named fceugx. Same thing, open it and stick your NES roms in the roms folder here.
Your set. Have fun. If you are interested in backing and playing games on your USB drive/stick. Go here: http://www.ehow.com/how_5302088_play-backup-games-usb-v.html