PS4 USB not reading?

So I just decided to replace my PS4 Pro’s HDD with an SSD. Samsung 860 EVO 1TB, however when I download the update file from playstations website, it downloads the file as a Adobe PDF file…? It’s suppose to be a PUP file. Has anyone else had this problem? It keeps saying the USB isn’t connected whenever I go to download the file onto my PS4. I’m assuming the Adobe download is what’s messing IG up. My computer won’t let me download it onto a PUP file as every time I click “Save as” the only option is Adobe Reader…?