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PC Build 16226 - Install Fails Due to .NET 3.5 Migration

Jason[MS] started on

Hello Insiders!

Today we have released build 16226 for PC to Insiders in the Fast ring.  As part of this release, there’s a known issue that will affect some users during installation.  Please read below for additional details:

Issue Details:

Who:  Insiders installing build 16226 to their PC

IssueYour PC may fail the install during the SafeOS phase of the install (“Working on Updates” between 0% and 30%) and roll back to your currently installed build

WhyThere is a known issue with the .NET 3.5 migration that causes the new OS installation to fail.  This issue only affects build 16226

What to doThere are no lasting effects from this issue.  Please see the workaround steps below to bypass and re-try the update

Workaround Steps:

Before attempting to install build 16226, or if you have .NET 3.5 installed and OS build 16226 install fails, complete the following steps:

(If you have not yet attempted to install 16226, skip to step 3)

  1. Wait for your PC to successfully roll back to your current build
  2. Log into your machine
  3. Open Control Panel
  4. Select Programs
  5. Under “Programs and Features” select Turn Windows features on or off
  6. Un-select the box next to .NET Framework 3.5 (includes .NET 2.0 and 3.0)

  7. Click OK
  8. Allow Windows to complete the necessary removal operations
  9. Reboot your PC
  10. Navigate to Settings > Update & Security > Windows Update and attempt to install 16226.

Build 16226 should install successfully.  Once the install is completed, please return to step 3 and re-install the .NET 3.5 feature.  Reboot your PC one final time and you should now be updated and ready to go.  If you encounter any issues, please post up and let us know!

As an additional note:  the underlying bug for this issue is understood and we are expecting to have a fix in place prior to the next build release for Insiders.

Thank you as always!


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