Windows 10 Insider build 21387 drops IE 11 and Task Manager’s new Eco Mode

Microsoft has just released the Windows Insider build 21387 for Dev Channel Insiders, which includes no new features and actually removes two things from the OS. The soon-to-be-retired Internet Explorer 11 is gone in this build, and so is the new “Eco mode” feature in Task Manager that made its debut in an April 21 flight.

The new Eco Mode in Task Manager could throttle process resources for certain apps to give the priority to other activities, but the Windows Insider team has removed it in this build “in order to refine the experience and address several issues thanks to Windows Insider feedback.” Today’s build 21387 also brings various bug fixes and you can check the full list below:

Changes and Improvements

• The Internet Explorer 11 desktop application is now retired as of this Insider Preview build. For additional details see https://aka.ms/IEmodeblog.
• 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.

Fixes

• 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.

Known issues

• The Windows Camera App currently does not respect the default brightness setting set via the new Camera Settings page.
• We’re investigating an issue where elements of Search (including the search box in File Explorer) are no longer displaying correctly in dark theme.
• [News and interests] We’re investigating an issue where the flyout may occasionally flash in the top left corner of your screen after clicking the button on your taskbar.
• We’re working on a fix for a second issue causing some devices to fail when updating to this build with error code 0xc1900101. When the update fails, it will roll back to the previous build. If you are encountering this issue, we recommend pausing updates until we release a build with the fix.

It’s pretty rare for the Windows Insider team to release new builds on a Friday, and today’s flight is definitely a minor one. With Microsoft’s Build developer conference set kick off next week on May 25, we hope that the Windows Insider team will use this opportunity to flight another build with interesting new features.