Instructions
Visit a website that hosts emulators, such as Emulator Zone, Enter the ROM or NGEmu (see Resources). Select the gaming console you want to download.
Visit a ROM website to download Mario games, such as DopeROMs, ROMNation, ROMHustler (see Resources). Every ROM game is in .zip format; however, you do not have to unzip them to play on an emulator. The emulator recognizes the ROM.
Install an emulator you want to use to play the Mario games. Installation only takes a few seconds.
Load the ROM. Emulators have a "File" menu. Search for the Mario game on your computer and click "Open."
Run the Mario game. Some emulators load the game automatically. If not, click "Run (image)" and you can play the game.