After having the computer crawl all day long, I decided to go back to the last restore point. What do you know? There was a critical update sent by Microsoft last night.
The updates seem to cause problems for me about 40% of the time. I know. I know. I should switch to a Mac.
I haven’t had this kind of history until Windows 10, which I view as an absolute disaster. You’d think Microsoft could make it so their updates weren’t so buggy.