I did a windows 10 download on two lap tops and it went just fine. didn't lose a thing. first computer I used the wrong pass word for the router and it would not connect. tried to get the window to enter the new pass word, but no way. So I went back to 8.1 and I got the log in screen and it was just fine, so I reloaded 10! would not log on to the router and gave me the same answer as before, so I'm back to 8.1. the other computer works just fine with 10. Pretty simply but took maybe 2 1/2 hrs. I had installed a new router so thats why I had to log on to the WiFi.