Caporegime
I would try reinstalling Windows from scratch and installing only the absolute minimum you need to get things working. I always hear the Digital Foundry team saying they have to reinstall Windows to try some problem solving. In an ideal world, we would all have two systems - one for purely gaming and one for day-to-day work/home stuff. That way it would be pretty easy to keep Windows 10 in a good condition. (My excuse for wanting a gaming PC and a new iMac. )