Fix your 8.1 before you install, k? And back it up. Then do a clean install of Win10, because -- as I found out when I did what I'm suggesting to you -- EVEN THOUGH I did a clean install, Win10 did copy my 8.1 settings and the INITIAL 8.0 theme I had partly configured. That caused a lot of problems, as the partial theme was not complete owing to glitches in customization that had to be resolved over the phone with MSFT. The only resolution was to redo Win10's themes, which took some hours to figure out.
So Win10 will look at your existing installation and key off it. So either install Win10 to another machine, or do a complete restore or something to get your 8.1 in shape.
(Away, Notifications Off) AUDIT PREMISES, my guidon. -- brainout or brainouty on vimeo or Youtube, domain brainout.net