Instructions
Download the SNES emulator ZSNES (see Resources).
Search for and download SNES roms. Roms are the versions of SNES games that are played in an SNES Emulator. You can find these roms by using your favorite search engine. SNES roms can also be located and downloaded from Cool Rom and Rom Hustler (see Resources).
Plug a controller into one of the USB ports of your computer if you own one. Otherwise, you can skip to the next step.
Open ZSNES.
Click "Config" at the top of ZSNES. Select "Input." The Input Device window will open.
Click on the "Keyboard/Gamepad" option at the top of the window. Then, click "Set Keys."
Assign keys and buttons on either the keyboard or the controller for each necessary button on the ZSNES. Each time you press a button, you will then go to the next corresponding button. Continue doing this until you reach the end. Then, close the Input Device window.
Click "Game." Select "Load." Search for the folder that contains the SNES roms you downloaded.
Double-click on the SNES rom you wish to play. That game will then open in ZSNES.