A BIOS file? Do you mean ISO file?
If you mean the ISO inside of the 7z you got on this website, you don't extract the iso, you put the iso itself in a folder of your choice.
"NintenDON'T sue me please haha"
How do I convert the Destroy all humans 2 copy into a BIOS file? Every time I extract the file it turns into 3 different folders and couple other files.