If you're using Windows 10 then you should, by default (if I recall correctly) be able to open them by default.
If you aren't using Windows 10, Download 7zip or Winrar (Make sure you get it from the official websites) and then extract the file you need to play the game and put it in a folder of your choise.
7z, rar and zip files are all compressed files btw.
"NintenDON'T sue me please haha"
Hello! My roms aren't giving me the option to open the zip files or extract anything from them. They're just saving as "7z" files with the internet explorer icon, and I can't even open them or save them as anything else. Anything I can do to fix this?