Error 0x80190001 seems to equal "you're dead to us"

[message found in a virtual bottle, apparently sent out by some isolated castaway]

Hi, I’m a reasonably proficient amateur PC user. My machine uses Windows 10 64-bit with Office 365. My Office subscription is active – at least, we pay for it every June. For the last couple months, my OneDrive hasn’t been able to sync; but I don’t use OneDrive much, so this didn’t worry me as much as it should have. A couple days ago, my Word and Excel programs began telling me that they were disabled because they were unregistered.

I tried restarting the machine and I’m able to use it, even though it still says I’m unregistered. But I can’t run Windows Update Troubleshooter – when I try to log in, I can’t access the password window. Instead, my email address returns “error 0x80190001”.

Same deal with Office 365 – it won’t even reject my password, won’t let me even try to log in. I use Word and Excel for everything; this is not good.

Oh, and Microsoft Support requires me to log in through my Microsoft account. Error 0x8019000.

I’ve no idea how to access Microsoft directly or who to ask or what to ask them. Can you guys help?

Thank you…

[end of bottled message]

I have no real advice, but when I googled that it sure returned a lot of stuff. All I can think of is to keep digging through those results.