Windows 10 Feature Update 2004 taking too long to install

Hopefully, someone will stumble onto the issue's rix and post the solution. It may not come from Microsoft.  It might be nice to post a list of things that don't fix it, so we users can use a process of elimination.

Good point...I'll start. Everything suggested by others previously, including yours, I've tried...makes no difference. The only thing I haven't tried is contacting Microsoft directly. Without going into too much detail, I have a better chance of resolving this myself and, quite frankly, I'll format the hard drive and "start over" before spinning my wheels in that process. It's not quite a knock on Microsoft, their server-side and Azure (recovery) support engineers are phenomenal, but my experience in the realm of endpoints (Windows and Microsoft/Office --> 365) isn't quite the same...historically, the end result resulted in "contact your hardware vendor" (Windows) or re-install Office or Windows (365)...none of which proves worthy. The customary finger-pointing game gives me heartburn and the server/Azure engineers do very little, if any, of that.

Not yet up to 28 attempts, but right there with ya.

How is it that random nitwits can design a piece of malware that can skip easily past firewalls, antivirus apps and other security fixes, but Microsoft can't design an update to their own OS that will install without issue?

Be careful, the same nitwits writing malware might be the same who design said W10 updates - outsource everything! LOL

Hopefully, someone will stumble onto the issue's rix and post the solution. It may not come from Microsoft.  It might be nice to post a list of things that don't fix it, so we users can use a process of elimination.

Not yet up to 28 attempts, but right there with ya.

How is it that random nitwits can design a piece of malware that can skip easily past firewalls, antivirus apps and other security fixes, but Microsoft can't design an update to their own OS that will install without issue?

These are some process, test to run ahead of time.

The process to run an In Place Windows 10 Update - keeping the existing Programs and Files takes many steps. This did not fix my long Windows Update either. But, some have claimed it helped.

My plan is to install:  2020-09 Cumulative Update Preview for .NET Framework 3.5 and 4.8 for Windows 10 Version 1909 for x64 (KB4576947)

Then, locate deep clean for the various Free Malware Updates that Oracle, Flash or other software updates try to install. This includes PDF updates, and removing any old Microsoft .NET Framework versions.

--------------------------------------------------- Free - Do This anytime --------

Open This PC in a File Explorer window. Select C: drive. Right click on Properties - find the Disk-Cleanup and run. Note: once the disk-Cleanup is run- there is another button below for Administrators only - Clean up system files. Run this one too. (Warning: do not do this if you have a Pending Update requiring Reboot - do this AFTER all updates are completed)

This can take around 30 minutes. User must be able to run as ADMIN. Copy and past the dism statement below into the CMD (command) window.

1. Press Windows Key + X to open Power User Menu. Select Command Prompt (Admin).
2. When Command Prompt opens enter dism /online /cleanup-image /restorehealth and press Enter.

Most places forget to mention - REBOOT right after running DISM.

Then follow the same steps above and run SFC /scannow

Again, several sites warn to immediately reboot when SFC end.

I have done all of the above multiple times - there is No Difference. 

However, it is important to do this or a Support Call will just ask for this to put off any real support. My Check for Updates takes around 40 minutes, even if there are no updates. My Internet speed is Gig service, Desktop is i7, RAM is 12 GB I have another i5 Desktop that takes approx 35 seconds.

----  Additional Test --- Consider Run this just to eliminate other issues

Found article that solved this by replacing a RAM Memory Chip. Chip was determined to be bad by running the:         MemTest86+

Please check out this site before using. This is Not a Built-In Microsoft tool. 

https://www.memtest86.com/

Search for: What are the license restrictions on MemTest86 Free Edition?

MemTest86 Free Edition is free to download with no restrictions on usage.

Before starting - a USB is needed - it will be formatted to run this test. Suggest creating a Restore Point for your Windows beforehand.