Help me with zip unarchive

Hi
when I unarchive some zip files I get a .nds file which I drag in and no problem with it.But other files unarchive to give folders containing 2 files- one is a .nfo and one is a .dizI tried dragging the whole folder into the ds but it didn't work- do I have to convert these files or what???Help me- I am completely stumped

those two files are not roms, they're extra files that are usually supplied and have nothing to do with running the rom. There should be an .nds file in there somewhere, this is the rom