Here's what's wrong with Windows 8.1

For most of us who downloaded Windows 8.1 from the Microsoft Store to upgrade our Windows 8, using our legitimate Windows 8 Product Key, there is no solution to this problem of corrupted files in Windows 8.1 because there is no legitimate ISO of it, and the Windows Store does not let us re-download it again to repair its problems. 

There's an unofficial 'work-around' for this, involving tricking Windows Downloads into thinking we're really downloading another copy of Windows 8 when in fact we're switching that during the process onto Windows 8.1, but the point here is that I shouldn't have to play hacking tricks with Microsoft to get a legal copy of Windows 8.1 repaired and functioning normally and testing as being complete.

And while I'm ranting about Win-8.1, take a look at my CPU graph in the little gadget on the sidebar. See those constant spikes? My Windows 7 and my Windows 8 Pro on the other computer don't do that. Their graphs are fairly smooth, and barely showing activity at all normally. And this tests clean of any infection with three different security programs, so it probably isn't infected.
So that's another problem not yet recognized or solved by Microsoft in Win-8.1.

My cure for all of the above is going to be to wipe Windows 8.1 and lose my files and revert that partition back to Windows 8 Pro the hard way, with a clean install. I've had it with Windows 8.1. This is both frustrating and ridiculous.