> I have two roms (galaga and 99 The Last War). I've tried a few emulators but it would > produce error messages when I try to play the games. Any help would be greatly > appreciated.
Hi!
Have you read the official project documentation? It's pretty good at helping you get up and running with a minimum of fuss: http://docs.mamedev.org/
It's most likely that you're downloading outdated ROM sets, or ROM sets that need a parent or device set in order to function properly. You should have a read through this page, as it does a great job of explaining how that works: http://choccyhobnob.com/articles/demystifying-mame-roms/