I was using Windows 8.1 on a computer I got about four years ago, and new printer would not work with it. I was about to give up and take it in to be fixed, but I finally figured out that I needed Windows 10 to run the printer.
I found a free upgrade on the the net and got it to work, seamlessly, with no loss of my files.
Did not need to pay a computer person. So relieved, as I had to put 140 into my other computer.