Sega dreamcast rom

I would like some help on a game. The game or rom i am playing is called "Armada" i did what i was suppose to do.but i get this message" wince not not currently available" All the other games i play are fine from here. Armada is also from here.i did these steps in order..1). Download game.2)7zipped it.3).scanned file.4).moved file to the desinated folder which is my dreamcast folder within a folder.5)make sure game works and it did not.! Please someone figure this out please thanks.