KB4474419 will not install

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.

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...

you would need to assign a letter to it first, because it is hidden by default in any Windows OS. You should be able to use windows mmc console with disk management tool to do this. Once letter is assigned you will see just as another drive:

Also running this should clear some space

https://answers.microsoft.com/en-us/windows/forum/windows_7-performance/system-partition-nearly-full-how-can-i-find-out/d344e28c-8471-4ae4-99c1-cbf6ff55386b

In my case I needed to get into system volume information folder and get rid of log files

I would agree with Koutheir Attouchi...I did a custom installation, I have no such partition, the drive was partitioned pre-installation, because I always do that, I'm not putting data in danger by putting it in the same partition as windows, everything boot related is in C:\ too for me.

So I guess that is a no go.  I need all the details first before I go ahead and perform open heart surgery on my OS ...LoL