We couldn’t complete the updates. Undoing changes. Don’t turn off your computer.

I signed out of my user/administrator account and signed back into the main Administrator account. I downloaded and ran the 21H2 helper app, which then downloaded the main 21H2 software. After two hours, I got the dreaded 'undoing changes' and another hour's wait undoing them all. That now seems to have used up the last option to get the latest update.

This has probably been asked already, but Is there are human-readable update log somewhere?

Perhaps do it exactly like I did: try to install 21H2 not from your normal Windows user account but from what is known as the built-in Administrator account. If you guys are using "pro" version of windows then this Administrator account already exists and is visible and listed among the users and all you have to do is login. But if it is the "Home" version of Windows you have (very likely the case if your current window came pre-installed when you privately bought your machine for personal use) then in that case this built-in Administrator account is dormant and not turned on by default and therefore not visible in your list of users. But it is there. You just have to first turn that on in settings/control panel or via powershell (unless you are like me and have that thing already turned on and available at some point previously, from which is where I just updated my machine into 21H2, and not from my normal day to day user account (never mind that this user account also has administrator privileges, don't forget this is the strange quirky world of Microsoft). And careful I'm not talking about creating a new account and naming it "Administrator" but rather activating an account that is already there hidden and disabled in your pc and already has "Administrator" as username, which is why it's referred to as "built in". It used to be not hidden in Windows 7 but I digress. Once you have fired that up, login to it and from there try to go to the microsoft.com link and try manually updating your machine to version 21H2 then after that's finished go back to login with your normal user account. See if that works for you guys. Just one more trick you could try. We have to help each other cos Microsoft has abandoned us and "left us to our own devices" as the expression goes.... except in our case it's not an expression but literal.

Thanks that fixed this problem... 2 hour job.

I didn't think there would be much difference between the 21H2 auto update, and manually doing it.

What system do you use to stop auto updating?

The most I can do is a 7 day pause.

I have tried most of the other methods and they do not work.

I haven't tried the "groups policy" because that requires Pro version.

Haven't tried working on the registry.

That sounds a bit scary.

Best that I can do is turn it off in "services". But it requires continually going there to turn it off,

else it will turn back on again.

I had this problem. I concluded that it was either a corrupt version of windows, or a hard drive issue. When I first got the problem, I reinstalled windows and was able to download updates. The next big update came out a few weeks later and my computer wouldn't update again with same problem, 7% then restart then failed to complete updates message. I bought a new motherboard, CPU and copy of windows as well as a new hard drive. I haven't had the problem since. I've been able to update for the past 3 months. I would think about trying a new hard drive on your computer and see if that works. Don't expect help from Microsoft. They kept telling me to download the media creation tool which does absolutely nothing to solve the problem. I lost a lot of sleep when I had this issue, so I wish you good luck.