"registry database is corrupt"

Did you make any images of your system before you did the update and did you try to restore them?
That's what I would do if such a thing happened to me.
Would be the shortest escape way...

A system restore would be the first thing I'd try, it's probably the least invasive. If you don't have system restore restore enabled on your boot drive, that's an important thing to do.

Thanks for the suggestion re "images" Kees but I have no idea what an image is. I am surprised that the update process is not designed to allow for fallback.

Thanks gunrunner for your suggestion about a system restore. I guess I had heard about restore points but guessed that a plain vanilla user like me would never need one. (My system is really simple!) I am looking at the dialog for system restores now. I have the option of creating a restore for my D drive. I have no idea where my D drive came from. Do you think I should create a restore image for it? There is also a drive named "WinRE_DRV" - I have not idea what it is or where it came from.

Should it be sufficient to create one only for the C drive?

Thanks, Bob

An image is an axact 'mirror' (sort of backup) of a (system) partition, taken at a certain moment.
There are many apps to do that, some of them are free.
One of the free ones is Hasleo, which is described by @antspants in this thread:

But if you don't know what an 'image' is, you certainly will not use such an app.
For the future I strongly advise you to change your habits and make backups of your system partition on a regular base.
I do that every time I changed some things in my system and/or when a main Windows update is to be done.
In that way I always can go back to the former situation before the update.

But for now, that will not be a solution for you.
Do you have system restoration activated? In that case you might try to restore the system to a former restore point.
Edit: In the meantime you have responded to the restore question. @gunrunnerjohn will be more familiar with that than me, because I always switch off making restore points as soon as I install a system.

Otherwise I would not know how to get out of this problem, other than using Dism or doing an 'In place upgrade'
For which you can find a Tutorial here:

I would try to do a repair on the Teams app it is referring to. Look in Settings-App-Installed Apps. Find Teams and you may have the option to Repair and/or Reset if you click on the ... for that app.

I would uninstall Teams Uninstall Microsoft Teams - Microsoft Support

If you do not use it, that's it. But if you do use it, to get it back do an online repair of Office. Repair an Office application - Microsoft Support


Only upgrades allow rollback. Recent regular updates can be uninstalled. You can see which ones you can uninstall by going to settings>windows update>update history>uninstall updates

bob17821 said:

There is also a drive named "WinRE_DRV"

Click to expand...

You should leave that alone as that is the Lenovo Windows Recovery Environment (WinRE) partition.
It can be used to repair or restore the system like it was when it left the factory.
Normally it is a hidden partition.

Microsoft Teams, msteams_autostarter.exe
The latter appearing in Startup Apps.

Installed Apps > Microsoft Teams > 3 dots > Advanced options.
Runs at log-in > Off.
Reset > Repair.
or Uninstall.

Assuming it is installed and you don't use the App.
Open MS Teams and configure it's settings.

3 Dots > Settings > General.
Untick:
Auto-start Teams
Open application in background

You might also go the MS Store and update, Microsoft Teams is in there, possibly installed from there. There has been a recent slew of updates in the last few days.
These will likely correct configuration registry database, that is of course guesswork.

On mine that msteams_autostarter.exe is shown as Disabled.

WINRE_DRV is the Lenovo recovery partition. I would not meddle with that.

You want to configure recovery for the boot drive, that would typically be the C: drive. Obviously, if that's not setup, it's too late for this problem.

Search for "System Protection". You'll see "create a restore point", select that. On the screen below, check and see if System Protection is enabled on the system drive. If so, you can do a system restore and see if that solves the problem.

Try reinstalling MSTeams and it may cure the issue.