It will come as a great shock to me if you are able to fully download and activate Windows 10, which Microsoft ceased as a freebie last Friday. You may get as far as 99% and that's your lot; without an activation key for an up-dated Operating System.
Furthermore, it is very unlikely that you will be able to get a genuine copy of W10 for less than £80/90. Pirated copies will cause all sorts of problems. They'll work for a while and then the problems start, without there being a way back to your present system, which I would think is quite sound for at least a further four years.
I have refrained from 'updating' because I took the view ..'If it aint broke, don't fix it.'
You are obviously quite at liberty to disregard anything which I have said. However, I and possibly other ABers will be very interested to know how you get on with matters.
Hans.