Software update OS X 10.9.5 Macintosh
I am trying to update the software of my Macbook Pro OS X 10.9.5 Macintosh that I purchased in 2013. The Monterey is not compatible but the Big Sur is. When I download it, it will not complete downloading. When I go to apple support and place in my serial number that I obtained from About this Mac, as well as from the bottom of my Macbook, it tells me the serial number is for a different product. I don't understand.