Hi.
Once you download the windows ten setup tool from microsoft, run it and it will start installing windows ten, that will take about half an hour, depending on your internet speed; then your computer will restart twice or three times, what the program is doing is installing the necessary files that are needed to run the OS.
Tip; You can run narator while this is going on by pressing and holding down the windows key and pressing the enter key.
Hear are the narator shortcuts you'll need:
To move left and right, capslock key plus either left or right arrow.
To click on an item; Capslock key plus space.
That's all you'll need for narator.
Once everything is set up; NVDA should start talking straight away.
I'm not sure on a full delete and install windows thing since I've not done it.
I hope this helps and if not, I'm sure someone else will help on this thread.
I'm gone for real :)