/Windows update destroyed my computer, how do I recover from this?

Unfortunately, you will have to perform a new install. This appears to be a serious bug many are encountering with the new version of Windows 10.

I am going to recommend you downgrade to Windows 10 1703.

Yes, not the best news you want to hear. These feature updates are not thoroughly engineered and are rushed mostly to meet deadlines. They have become highly unnecessary in some instances. My opinion, focus on the apps and less on having the latest version of Windows. If your apps are working fine and you are getting your work done, minimize your need to jump on the latest release.


Now, get ready to go back to your previous version. I recommend Windows 10 1703 because its the most stable and efficient release to date.


Step 1: Go to another working computer with Internet access, download Windows 10 1703 from the following link:
https://tb.rg-adguard.net/index.php?sid=74a7cf5...

Choose the following:

- Windows Final
- Windows 10, version 1703
- Windows 10 Pro + Home
- English
- x64 (64 bit) x32 (32 bit)

Step 2: create a bootable copy
https://answers.microsoft.com/en-us/windows/wik...

Step 3: perform a custom install
http://answers.microsoft.com/en-us/insider/wiki...

Step 4: how to recover your files from Windows.old:
https://answers.microsoft.com/en-us/windows/for...

There seems to be some early adopter issues at this time with Windows 10 1803, if you can, I recommend you downgrade to your previous version until the Spring Creators Update matures with future cumulative updates.

Windows Update might attempt to upgrade to Windows 10 1803 again. See instructions how to block it:
https://www.groovypost.com/howto/block-windows-...

Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.

Sorry, this is widely reported currently and there is no known fix except to do a clean install or a Reset or wait until MS comes up with a workaround.
https://www.yourwindowsguide.com/2018/05/what-i...
Disclaimer:
This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.
Some people report Disabling Virtualization in BIOS or running Startup repair a couple of times worked.

If I follow this will I end up being asked for a key or something to activate the software?  This machine was upgraded from Win7, so I have no key or anything like that.

When you upgraded from a previous version of Windows or receive a new computer preinstalled with Windows 10, what happened is the hardware (your PC) will get a digital entitlement, where a unique signature of the computer will be stored on Microsoft Activation Servers. The Windows 7 or Windows 8 genuine license you were previously running will be exchanged for a diagnostics key.

Anytime you need to reinstall Windows 10 on that machine, just proceed to reinstall Windows 10. It will automatically reactivate. You will prompted to enter a product key a couple times through the installation, click I don't have a key and Do this later.

There is no need to know or get a new key, but if you have issues with Digital Licensing or the Activation Troubleshooter, you can utilize an existing Windows 7 or Windows 8/8.1 product key you already own to reactivate if necessary. or use the reset function in Windows 10.

Thanks.  I forgot to ask.  Does the new install entail erasing all my files, or is it like a "reset"?  Since this is a software problem, I think my files are intact if I had a means to get at them.  Taking out the hard drive and putting it in a USB enclosure would be a last resort, but hopefully there are easier options.

Oh yeah, can you confirm that the password it wants is my Microsoft account password, the last one it was aware of anyway?  If I can guess that, am I good to go?

If you perform a custom install, your files will be archived to the Windows.old folder where you can recover them.

I recommend you first setup with a local account first, then sign into your Microsoft Account after.

Your Microsoft Account password should be same as it is now:

Open Start > Settings > Accounts > Your info

Click sign in with a Microsoft account instead

Enter the email address of the account you want to use
Click Next
Enter your Microsoft Account password
Enter the current Local account password used to sign into the account
Click Next and you should be signed in with the new account.