You need a xz archive unarchive program. Your extension is openining with adobe for some reason. You have the right file just not the right app to open it
Don’t double click the file or open the link, this simply causes the rogue file extension association to try to use Acrobat Reader to open it. Instead, fire up the WinZip program and use file->open from there.
Can you see the downloaded file in File Manager in your download directory? If you can, try right clicking and using “open with”. Sorry, I’m not a Windows user and this sort of nonsense (your OS, not you) is not making me nostalgic
Here’s a quick fix to try. I’ve compressed these as a zip and stuck it onto a server for now. This might be easier to deal with (do ask yourself if you trust me first ).
Double click, this should open automatically using built-in zip support on windows. Then copy the file called ffmpeg across to the ROCK box’s /Data/Codecs directory as per the instructions.