Microsoft cuts Internet Explorer in latest Insider build of Windows 10

Surface Laptop 3 13.5
Surface Laptop 3 13.5 (Image credit: Daniel Rubino/Windows Central)

What you need to know

  • Windows 10 Build 21387 is rolling out to Insiders in the Dev Channel.
  • The build marks the retirement of the Internet Explorer 11 desktop application.
  • Microsoft also turned off the "Eco mode" feature in the Task Manager as it refines its experience.

Microsoft just rolled out Windows 10 Build 21387 to Insiders in the Dev Channel. The build doesn't have any new features, but it does remove or turn off some notable features. Starting with Build 21387, Microsoft has retired the Internet Explorer 11 desktop application. This comes as no surprise, as Microsoft already announced the end of support for Internet Explorer.

The build also turns off the "Eco mode" feature in the Task Manager, though this feature seems set to make a return in the future. In the release notes of Build 21387, Microsoft explains that the feature was turned off while it refines the experience.

Here are all of the changes found in Windows 10 Build 21387:

  • The Internet Explorer 11 desktop application is now retired as of this Insider Preview build. For additional details see
  • We are turning off the "Eco mode" feature in Task Manager in order to refine the experience and address several issues thanks to Windows Insider feedback.

There's also a long list of fixes in the build:

  • We fixed an issue in the previous flight where during the upgrade and in the welcome screens displayed after first sign in, the text was unexpectedly using the Times New Roman font.
  • We fixed an issue resulting in some Insiders seeing errors when trying to launch Notepad via the Run dialog.
  • We fixed an issue for WSL users, preventing some Linux GUI apps from launching correctly via the shortcut that is automatically added to Start menu.
  • We fixed an issue resulting in the reset or change PIN workflows not working.
  • We fixed an issue where for some Insiders, night light was immediately turning off after being enabled.
  • We fixed an issue in recent flights where you might unexpectedly get a "We can't find an audio device" error when trying to play audio from a connected Bluetooth speaker.
  • We fixed an issue where explorer.exe might crash after repeated use of the touchpad gesture for switching Virtual Desktops.
  • We fixed two issues impacting the ability to print using USB printers.
  • We fixed an issue resulting in the Windows Update page potentially becoming unresponsive after clicking Pause Updates.
  • We fixed an issue causing some devices to fail with error code 0xc1900101. While this fix will resolve the problem on some devices, there is a second issue causing the same error code (noted below). We're working on a fix for this issue as well.
  • We fixed an issue where some devices were re-offered the .NET update after it is installed. After taking this build you should no longer be reoffered the .NET update. If you experience and issue getting Build 21387 because of a pending .NET update, you can work around the issue by pausing then un-pausing updates.
  • We fixed an issue where some devices would crash with a DPC_WATCHDOG_VIOLATION error when using OneDrive Personal Vault.
  • We fixed a ctfmon.exe crash when using ATOK (a third-party IME) if reconversion was triggered in some win32 apps.

You can grab the latest build now through Windows Update if you're a Dev Channel Insider.

Sean Endicott
News Writer and apps editor

Sean Endicott brings nearly a decade of experience covering Microsoft and Windows news to Windows Central. He joined our team in 2017 as an app reviewer and now heads up our day-to-day news coverage. If you have a news tip or an app to review, hit him up at