Windows 10 build 21286

Build of Cobalt
OS familyWindows 10 (NT 10.0)
Version number10.0
Build number21286
Build revision1000
Architecturex86, x64, ARM64
Build labrs_prerelease
Compiled on2020-12-18
Expiration date
Timebomb2021-10-31 (+317 days)
Home (China, N, Single Language)
Pro (China Only, N, Single Language)
Pro Education (N)
Pro (N) for Workstations
Education (N)
Enterprise (N, (N) Evaluation, G (N))
Enterprise multi-session
IoT Enterprise
Product key
Use a Windows 10 Retail serial
About dialog
21286 winver.png
TCB.png TCBGallery.png

Windows 10 build 21286 is the second Insider Preview build of Cobalt, the 21H2 development semester of Windows as a service. This build was released on 6 January 2021 to all Windows Insiders on the Dev Channel.

New features and changes[edit | edit source]

Note that some of these changes were only available to a small group of Insiders, meaning that not everyone was seeing them right out of the box. They're completely rolled out to all Windows Insiders on the Dev Channel starting with build 21359.

News and interests[edit | edit source]

Enabling News and interests[edit | edit source]

The News and interests feature was introduced in a controlled rollout, which includes it being disabled on clean installations. To enable it, make sure to have the Chromium-based Microsoft Edge installed, have the system region set to United States, Canada, United Kingdom, Australia, or India, and use ViVeTool to enable the following velocity IDs from an administrator Command Prompt window:


General[edit | edit source]

  • Storage Spaces can now be managed on Settings → System → Storage. However, the Control Panel page is still available.
  • Windows Subsystem for Linux 2 distros can now be configured to run any specified Linux command at startup. This can be accomplished by editing the /etc/wsl.conf file in the distribution and adding an option titled command under a section titled boot.
  • Some updates have been done for users that have configured the time zone to be set automatically in Settings → Time and Language → Date & time:
    • When the time zone is updated due to a high confidence detected location change, a notification will appear informing the user about it. The toast will include information about the new time zone and clicking it will open the aforementioned page in Settings.
    • If a low confidence location change is detected and there is a single administrator on the device, a notification will appear asking the user to update the time zone, and clicking the OK option will apply the change.

Bugs and quirks[edit | edit source]

News and interests[edit | edit source]

  • The flyout may show as offline even when the user is online.
  • Users cannot navigate into the news and interests flyout using keyboard.
  • In some scenarios, the flyout may appear empty with no content.
  • Sometimes the flyout cannot be dismissed with touch and pen.
  • The flyout uses more taskbar space on the left than expected.

General[edit | edit source]

  • The update process to this build has a chance of hanging for extended periods of time.
  • Games such as State of Decay 2 or Assassin’s Creed may hang or crash when launching.
  • Call of Duty: Modern Warfare and Black Ops Cold War may not launch starting with this build.
  • Some rendering / graphic issues may be experienced after resizing certain app windows. This should be resolved after minimizing and restoring all windows by using the ⊞ Win+D hotkey twice.
  • Some 32-bit systems may lose network connection after upgrading to this build.
  • When Xbox Game Bar is launched from the Start menu or via the ⊞ Win+G hotkey while using a text editor, the computer may appear unresponsive. If you encounter this, dismiss the bar with the same hotkey and end the GameBar.exe process from Task Manager.
  • Miracast users may experience very low frame rates in this build.
  • Explorer.exe might hang or crash in this build.
  • Live preview doesn't work for pinned site tabs on some machines, a gray window is seen instead of the intended content.
  • Aero Shake is disabled in this build. To enable it again, merge the following to the registry and restart explorer.exe:
Windows Registry Editor Version 5.00

Gallery[edit | edit source]

Setup[edit | edit source]

General[edit | edit source]

News and interests[edit | edit source]

External links[edit | edit source]