Last night when I was signing off, I got the flag on the Shut down button telling me updates requiring a restart were ready. I checked, one was a WD signature update and the only other was KB3194496.

I selected Update and restart, and once that began I went on to bed (I have scheduled tasks that run in the wee hours). When I signed on today, after a few minutes I got a notice that Windows Firewall was off and needed to be started. Only it wouldn't restart.

I got warnings that its settings weren't correct, but nothing I tried would get it started. I tried in Services, and that failed as well. I don't remember the error code exactly but the only search results I found had answers regarding Windows Firewall being shut down by default when a third party AV is installed. I don't have a third party AV installed.

I restored my OS partition Image For Windows drive image from a couple of days ago (in 3:15) and booted up. Everything was normal. I then opened Settings and checked for updates, got KB3194496 downloaded, restarted and everything's fine once more.

I have no idea what went awry, but the PC has been running normally all day.

Another testimonial for frequent drive images.