Having a bit of an issue with that took I have my key ok but its not been upgraded to windows 10 yet and as I did a clean install not an upgrade the windows 10 upgrade software is gone. Trying to get onto MS about it to see if they can help.
I have no complaints on 10. I should point out though its mining our data aggressively. While you can turn off some of the data catchers, others are built in. http://www.techworm.net/2015/07/by-downloading-windows-10-you-are-allowing-microsoft-to-spy-on-you.html
After installing the win 10 and it crashed like crazy with the autoupdate for my radeon amd, I discover that the problem its not the win 10, but the sony that don't permitted that I update my driver with a generic driver for the model that I have... So I'm back to 8.1 till some light from sony T-T"