See above
The process could be canceled and start over… Let it go. At some point he broke out…
Probably smeared
After so long, you have no choice but to restart. Usually this does not result in a software defect, and certainly not a hardware defect.
Over 24h?
Nothing will work there, not even in 100 years
Seems to be a current update problem. I had with a customer a few hours ago. There I could at least start the task manager and restart the PC with it. After that everything was OK.
Should the Task Manager not work, I would wait a little longer. There's the rare case that updates take longer than 24 hours. However, the HDD lamp, if present, should flicker all the time. Then something else happens.