Much the same for me but my trouble began last Thursday (10/Aug/17). It seemed as if new downloads were arriving but the frenetic disk activity hasn't stopped since. I was prompted then to allow Rptr (a gaming app I think?) to access my hard drive due to an update but I denied it. I've since uninstalled Rptr successfully but the drive problem persists.Same trouble with me but after much PC perusing by this non-pro, it seems to be a ghost in the system, flitting around spanking systems at random for seconds at a time - Pulling my hair out
Checking my downloads history, the only Windows download on the 10/Aug was for MS Photo. I tried to uninstall that but the uninstall button seems to be disabled for Windows software elements?
I searched for help & found the advice to troubleshoot & restart your machine but that didn't improve matters for my laptop. The one thing that has worked for me is restarting in 'Safe Mode'. My drive is now quiet & web pages haven't downloaded this fast in a long time! Of course the appearance is rather basic & graphics get stretched.
But this isn't a long term solution & I'm no closer to finding one - any advice please?