The .nfo file extension is most famously associated with from the Scene (warez groups like X-Force). These are plain text files, not media files.
Here is the complete guide on how to open x-force.nfo : Most .nfo files use ASCII art (logos made of letters and symbols). If you open them in Notepad, they will look like a mess of symbols. You need a viewer that respects the original layout. x-force.nfo how to open