I woke up the other day to my computer having rebooted itself for an update which deleted all of the work I had left open from the day before. A blue screen was asking me to do various tasks which I was too busy to do so I dismissed it with the only option that was to "remind me in a few days". There was no option to opt-out.
A few days later there is new a popup at the bottom-right corner of my screen. When trying to dismiss the notification it instead took over my screen. I clicked through a page or two to see what it was about before it told me that to proceed I would be required to attach a "Microsoft account" which I don't have.
I can't close this window with Alt-F4 or kill the process with Ctl-Alt-Del. Task Manager is also blocked as Ctrl-Esc does nothing. There is also no option to dismiss the dialog.
I don't have a Microsoft account. I have an account on this computer and this popup has taken over my screen. I can do a hard reset but this will again destroy the work I have open and for all I know it may popup again when the computer starts up.
Why am I seeing this and how do I dismiss it so that I use the computer that up until now I thought I owned.
Additionally, how can I prevent these kind of intrusive messages from appearing on my computer in the future?