How to roll back from accidentally released untested Windows 10 20H1 Build 18947

Windows 10 Build 18947

Recently, Microsoft accidentally released untested Windows 10 20H1 Build 18947 to all Insiders especially insiders on Slow Ring and Release Preview ring.

Microsoft explained what caused this error :

Windows Insiders may be wondering what caused this scenario.  We actively test and validate each of our preview builds internally before sharing them externally, however a configuration change allowed this build to release to multiple rings simultaneously, including external rings.  We have made the necessary remediation in our Flighting service and have implemented additional changes to help prevent from this happening in the future.  We apologize for any troubles this may have caused for affected Insiders and appreciate your assistance in bringing this to our attention so we could make the necessary changes as quickly as possible.

Microsoft said this build is designed for internal usage, this build contains many bugs. Microsoft recommends users on Build 18947. Insiders generally have 10 days after installing build 18947 to complete the rollback process and the time may be reduced if insiders have Storage Sense enabled. If you’re the affected users, you can rollback to earlier build by following the step below.

There are two things to do before you do the rollback process, Verify if your device has build 18947 and verify if Build 18947 is uninstalled.

Verify if your device has Build 18947

  • Click “Start”.
  • Type WINVER.
  • Select WINVER (Run Command).
Verify OS build number

You will see a resulting window showing which build number is installed on your device:

Result of the step #1

If the result shows you have build 18947 you can jump to “How To Rollback” section, if not you can go to the next steps, “verify if Build 18947 is uninstalled”.

Verify if Build 18947 is uninstalled

If 18947 is not installed, please verify if it is pending install by checking the following:

  • Click Start
  • Click Settings (the sprocket icon)
  • Select Update & Security
  • Select the Windows Update tab

Verify whether build 18947 is pending install

Rollback from Windows 10 Build 18947 #3
Rollback from Windows 10 Build 18947 #4

If your device has Windows 10 build 18947 pending install, you may select Pause updates for 7 days.

This will cause the pending install to be cancelled.  It may take a few minutes for this to register on the device.

Once this completes, it is recommended that you reboot your device and then return to this screen and un-pause updates.  You will not be re-offered the 18947 build and may scan for updates as expected.

After doing two steps below is time to do the rollback process.

How to Rollback

If your device has already installed build 18947, the next step to take is to complete a rollback on the affected device.  This process rolls you back to your previous build of Windows and will put you back into the proper state.

To complete a rollback, please do the following:

  • Click Start
  • Open Settings (the sprocket icon)
  • Select Update & Security
  • Select Recovery
  • Under “Go back to the previous versions of Windows 10” select Get Started

Complete the on-screen steps as follows:

a.       For “Why are you going back”, select “For Another Reason

b.       Under “Tell us more” enter 18947 

Rollback from Windows 10 Build 18947 #5

c.       Click Next

d.       On the “Check for updates?” screen, select “No, thanks” 

Rollback from Windows 10 Build 18947 #6

e.       There will be two more screens with information to review.  Please read each screen, clicking Next to continue.

f.        You will see one final screen.  Select Go back to earlier build to initiate the rollback process.

Rollback from Windows 10 Build 18947 #7

Your device will complete the rollback process and you will be restored to the previous build.

Source: Microsoft.