Although Windows 10 21H1 (also known as the May 2021 Update) is a minor feature update that does not require reinstallation on devices running version 20H2 or 2004, there are still chances of bugs and other problems that may cause the computer to stop booting.

If your device is experiencing problems and won’t even boot, you can still roll back to the previous version whether you upgraded using the enablement package or complete reinstallation. However, Windows 10 only gives you ten days to uninstall feature updates. After ten days, the only way to remove the May 2021 Update is by doing a clean installation of the previous version.

In this guide, you will learn the steps to uninstall Windows 10 version 21H1 using the Advanced startup settings when your computer won’t boot. If you still have access to the desktop, you can downgrade using these steps.

  • Uninstall Windows 10 21H1 from version 20H2 or 2004 with Advanced startup
  • Uninstall Windows 10 21H1 from version 1909 or 1903 with Advanced startup

Uninstall Windows 10 21H1 from version 20H2 or 2004 with Advanced startup

If you upgraded a computer running version 20H2 or 2004 using the enablement package, that is the quick update that does not require reinstallation, then you can roll back to the previous version using the Advanced startup settings.

To uninstall Windows 10 21H1 (May 2021 Update) enablement package when the computer doesn’t boot, use these steps:

  • Start the Windows 10 PC in Advanced startup.
  • Quick tip: Depending on the severity of the problem, you can access the Advanced startup environment in several ways. This guide will show you all the methods to access “Advanced startup” and then continue with the steps below.
  • Click on Troubleshoot.
  • Advanced startup troubleshoot
  • Click on Advanced options.
  • Advanced options
  • Click on Uninstall Updates.
  • Windows 10 uninstall updates Advanced startup
  • Click the Uninstall latest quality update option.
  • Uninstall quality updates when the PC doesn’t boot
  • Sign in using your administrator credentials (if applicable).
  • Click the Uninstall quality update button to remove the KB5000736 enablement package.
  • Uninstall Windows 10 21H1 (KB5000736)

Once you complete the steps, the computer will uninstall the Windows 10 21H1 enablement package (KB5000736) to roll back to the previous version.

Start the Windows 10 PC in Advanced startup.

Click on Troubleshoot.

Advanced startup troubleshoot

Click on Advanced options.

Advanced options

Click on Uninstall Updates.

Windows 10 uninstall updates Advanced startup

Click the Uninstall latest quality update option.

Uninstall quality updates when the PC doesn’t boot

Sign in using your administrator credentials (if applicable).

Click the Uninstall quality update button to remove the KB5000736 enablement package.

Uninstall Windows 10 21H1 (KB5000736)

Uninstall Windows 10 21H1 from version 1909 or 1903 with Advanced startup

Alternatively, if you upgraded a device running version 1909 or an older version, or you used the Update Assistant or Media Creation Tool, then you can still use the Advanced startup settings, but the steps will be slightly different.

To uninstall Windows 10 21H1 after full reinstallation, use these steps:

  • Start the Windows 10 PC in Advanced startup.
  • Click on Troubleshoot.
  • Advanced startup troubleshoot
  • Click on Advanced options.
  • Advanced options
  • Click on Uninstall Updates.
  • Windows 10 uninstall updates Advanced startup
  • Click the Uninstall latest feature update option.
  • Uninstall feature update when PC doesn’t boot
  • Sign in using your administrator credentials (if applicable).
  • Click the Uninstall feature update button to remove Windows 10 21H1.
  • Remove Windows 10 21H1

Once you complete the steps, the system will uninstall the Windows 10 May 2021 Update, and it will roll back to your previous installation.

Click on Advanced options.

Click the Uninstall latest feature update option.

Uninstall feature update when PC doesn’t boot

Click the Uninstall feature update button to remove Windows 10 21H1.

Remove Windows 10 21H1

The ability to remove a feature update is usually available during the first ten days after the upgrade process, but only if you have not deleted the files and the Windows.old folder is present in the root of the “C” drive.