KB4474419 will not install

Well, this could be your whole problem, windows requires reserved partition for proper operation.

When you create partitions using windows installation media it will always create one.

Maybe this can help you? But I would just let Windows re-partition the drive properly this time and reinstall it.

https://answers.microsoft.com/en-us/windows/forum/windows_10-windows_install/no-windows-10-system-reserved-partition-cant/8ee6cd40-8e5a-4ec6-9cc3-80a305a97eec

https://www.tenforums.com/installation-upgrade/10975-no-system-reserved-partition.html

Anyway, the fix worked in my case on all servers (about 8 of them), but it can be different for other people, you never know with MS.

I assume you have done already all the basic checks such as windows update readiness tool, resetting and rebuilding windows update cache, disabling AV, windows update troubleshooter etc...

The links you show mention Windows 10, not Windows 7. It is not reasonable to call a "fix" a complete reinstallation of Windows. If the system partition is necessary, then the Windows installer has a bug as it allows installing Windows 7 in a single partition.

The links you show mention Windows 10, not Windows 7. It is not reasonable to call a "fix" a complete reinstallation of Windows. If the system partition is necessary, then the Windows installer has a bug as it allows installing Windows 7 in a single partition.

Sounds like an IT manager we once had,  she would reformat everyone's computer the second she counldn't resolve a simple issue.  Most of us had to keep her away from our PCs with a baseball bat !