Update totally hoosed my system.

Booted up my main desktop this morning and it did what looks to be a big update. It tried to anyway. I got several messages along the lines of "improving security" "updating your Apps" etc. Large text on a blue background, like you see with the messages during an install. It was taking forever and stalled on a "this is taking longer than expected" message for 30+ minutes. Then an "almost done message" then just a blank screen with a mouse cursor. It sat there for 2 + hours with no hard drive activity. I tapped the power button and it shut down. This PC was already running 1803.
Booted up and it just stalled at the log on screen. I clicked my mouse to log in and it sat there with the juggling balls. My graphics driver was hosed too. My logon screen was on the wrong monitor and was the wrong resolution. Like what I get on a clean install with the stock windows driver. I tried to do a repair but that failed, as did system restore. Just finished doing a clean install. I was going to do one anyway, just hadn't planned on doing it today.

alphanumeric said:

Booted up my main desktop this morning and it did what looks to be a big update. It tried to anyway. I got several messages along the lines of "improving security" "updating your Apps" etc. Large text on a blue background, like you see with the messages during an install.....

Are you sure that wasn't the 'User First Sign-in Animation'? For screenshots, see this tutorial...
Turn On or Off User First Sign-in Animation in Window 10

You see those screens at the first sign in of an existing account after a Features Update, or when you make a new account and sign in for the first time.

Neither of which should have applied in your case, as you must have already signed in many times since getting 1803. I'm guessing you were not being signed in with your normal profile for some reason. Maybe using a temporary profile instead?

Fix You've been signed in with a temporary profile in Windows 10

That "could" have been what I saw? Like you say though, why this morning? I've logged in many times after upgrading to 1803? It totally screwed my system what ever it was? I could not log in anymore.

alphanumeric said:

... why this morning? I've logged in many times after upgrading to 1803?

As I said, it looks like it was not able to use your normal profile. The 'Temporary Profile' tutorial may hold some clues.

A bit late now if you've completed the clean install, but did you have another account you could try?

If you suffer this again, a useful tip at the "...just a blank screen with a mouse cursor" point is to try Ctrl-Alt-Del. Usually you can get to a blue option screen that way, from there you can start Task Manager, and from there you can run any new task you want (including a 'run with Administrator privileges' option). Running Explorer.exe may (or may not) get the desktop back, but running cmd.exe will certainly get the Command Prompt.

Only had the one account. My profile being messed up sounds like a good assumption. It was really slow booting up when that all went down. It took a longer than normal time to get to the log on screen. I did try ctrl alt del, didn't think to start a new task. Maybe next time, I really hope there isn't a next time though.

alphanumeric said:

.. I did try ctrl alt del, didn't think to start a new task. Maybe next time, I really hope there isn't a next time though.

Yes, if you can use Ctrl-Alt-Del then running an admin command prompt from Task Manager is a useful trick to remember.