So, I've had the wildest time trying to install update 20h2 (October Update) for Win10. It usually throws a bluescreen (page fault in nonpaged area) error and then reverts itself. I had a similar issue with a previous update, the solution was to disable my motherboard audio drivers from safe mode, then install further updates, and I would be able to re-enable the drivers without bluescreen. Simple enough.
For 20H2, it tries to install and then reverts the update after bluescreening. However, I had a lot of trouble even getting into safemode. My solution was to use install media to force a safe mode boot after the first bluescreen, but before it restarted and automatically reverted the update. This time, it made things worse. At the login screen, I get the message "there was a problem with your pin". Clicking "enter pin" gives a prompt to download a program from the microsoft store (presumably the login service) which immediately fails. I have not found anyone else on the internet who has encountered this problem. There is NO option to log in with a password instead. I know the password is still tied to the account because I need to use the password for a command line boot, which works. However, I have not been able to find a way to fix the pin problem from the command line. I was able to use bcdedit to get it out of safe mode, but this did not resolve the issue. Now I seemingly have no way of reverting the update (or even checking if the update is actually installed) or logging in, and my options from the login screen or command line are limited.
I also tried a system restore on two system restore points, both of which failed.
So, if anyone knows a way to fix this particular problem, or forcibly create a new login/disable the pin, I'd love it. I do have access to the system files from another operating system.