Once you've downloaded the full set of MAME ROMs, you'll need to install MAME on your computer. Here's a step-by-step guide:

MAME hides games that are missing required BIOS or CHD files. To see your actual full set, go to Available (not "Working" or "Original").

MAME's native UI is ugly. After downloading your full set, download a frontend:

If you're looking to download a full set of MAME ROMs, you should be cautious. There are sites that offer comprehensive sets, but these are often hosted in a legal gray area. Some sites might bundle games that are no longer under copyright with ones that are, complicating the legal status.

There are several ways to legally obtain MAME ROMs:

When downloading a full set, you will typically choose between three main formats: Where to get the latest Mame sets (Guide) - Noobs