My Windows 10 Version 20H2 will not install the update 0x80004005.

No luck at all. I give up. :(

And Gates wants us to trust him on a pandemic when he couldn't even protect Windows 95 from viruses.

This is around my 4th time trying to get my Win 10 update.  Last time it hung at 99% installed (yeah, really?) overnight & throughout the next day.  Disabling Symantec protection hasn't worked and other folks in our corporate deployment are having issues too. This is on Win 10 Pro version 1909 build 18363.1440 on my work laptop. Whiskey Tango Foxtrot?

My Win 10 Home running personal desktop was updated to 20H2 in about 15 minutes. Nothing special done to prep it. I selected the optional Windows Update to install it, rebooted the desktop, logged on, ran Winver and it shows 20H2 installed.

Seriously--WAY beyond my expertise level. Microsoft needs to come up with a solution that works for the average user. These updates are supposed to be essentially transparent to the user--not require an advanced degree in system maintenance. Near as I can tell from this thread, this problem has been going on for MONTHS, and I thought I saw the "me, too" count around 2500.

You are absolutely correct.

We spend ~ 20% of our time using this now broken-down software; and ~ 80% of our time fixing issues created by Microsoft. I would be humiliated if I created a product and when my customers had problems, I basically could not, or would not fix them. A problem here or there that is fixed in a timely manner is understandable; but these issues are ignored and some literally go on for years. And reloading Windows is NOT a fix! It is simple a way out that costs MS nothing; but the users are expected to commit extensive time out of their lives to start all over.

Also, this is usually the "fix" for issues with Office 365.

Ditto what the last guy said.