Microsoft is an exemplary trailblazer in the IT-sphere. The Insider program is one pioneering strategy that shapes its upcoming features. Here is a guide on how these builds in the Windows 10 Insider Program have evolved through time.


Probably no one can beat Microsoft when it comes to innovations. The organization rolled out the Insider Program as an open software testing platform to allow users improve the Windows 10 OS. Since the day of the inception of the Insider Program in 2014, millions of tech enthusiasts and beta testers have signed up for the program. 

As a part of this program, there are three channels or Insider “Rings” to choose from: the Fast Ring, Slow Ring, and Release Preview Ring. Fast and Slow Rings are otherwise known as the Dev and Beta Channel. The Fast Ring receives the most regular updates and offers the latest software. The Dev Channel is also the least tested and the most unstable, and hence the riskiest ring to choose. Not every ring makes it from the Fast Ring to the Slow Ring as the one that reaches Beta Channel must be more stable and tested.

On the other hand, the Release Preview Channel sees no action until a new feature update is rolled out. The last channel is meant for final testing for a new release and is best for testers who want to work with the most stable builds. 

Here is a brief detailed timeline of seven recent builds in their chronological order in the Dev Channel and an overview of what they hold. 


Dev Channel Preview Builds #1 Windows 10 Insider Preview Build 20279 (FE_RELEASE)

Release date: December 14, 2020

This one is almost the same as Build 20277. Microsoft launched this build to test its credibility to swiftly precede one build with the other. Insider users who updated the 21277 builds aren’t provided with this build because they are on a newer build. 

#2 Windows 10 Insider Preview Build 21277 (RS_PRERELEASE)

Release date: December 10, 2020

The Build 21277 is being offered as an optional update via the seeker experience in the Windows Update. Once users install Build 21277, they will continue receiving the RS_PRERELEASE builds. After they switch to this build, they cannot switch back to the FE_RELEASE build. There are major bug fixes in the 21277 build, and it adds support for Emoji 12.1 and 13.0 and offers x64 emulation in Preview. There is also an updated animation while opening or closing a window to make the transition look smooth. In the new build, users can uninstall the Snipping tool and reinstall it via the Optional Features Page in Settings.

#3 Windows 10 Insider Preview Build 20277 (FE_RELEASE)

Release date: December 10, 2020

There are two significant bug fixes in this build. For one, it fixed an issue that could result in losing the WinRE volume label. Secondly, it fixed the bug that resulted in apps failing to update with error code 0x80073D02. However, there are several known issues with this build like the update process hanging for extended periods, live previews not getting enabled for punned sites, etc. Also, users had to manage their disks using the Classic Disk Management tool because the update process hangs for an extended period. 

#4 Windows 10 Insider Preview Build 20270

Release date: December 3, 2020

This is an all-time favourite build upgrade that bought Cortana to the limelight. This build gave Insiders the power to use Cortana on their PCs to find and open files. This saved them navigation time and helped them to easily locate the information that they are looking for. Other improvements included the new Advanced View checkbox to Optimized drives and updates in the touch keyboard portrait posture by adding a split keyboard mode. There were bug fixes as well related to dialogs, unexpected shutdowns, delayed logins, etc. There were also some known issues. One of them includes no availability of drive under Settings > System > Storage > Manage Disks and Volumes. 

#5 Windows 10 Insider Preview Build 20262

Release date: November 18, 2020

The Build 2062 mainly featured bug fixes resulting in unexpected app launches with no visible content. Other fixes related to:

  • Old SleepStudy etls not being cleaned up
  • Notifications related to block at first sight not being localized
  • Touchpad scrolling no longer no loge working after closing a browser tab using CTRL+W
  • Settings crashing while uses navigating to Storage sense
  • Issues related to app registration or some default apps

#6 Windows 10 Insider Preview Build 20257

Release date: November 11, 2020

The 20257 build facilitated the Insiders to interact with multiple Android applications simultaneously on their Windows 10 PC. It kind of evolved the Phone apps experience and offered the convenience to Android users to run several apps side by side on their Windows 10 PC. With this update, Insiders can pin their apps to Windows 10 Taskbar, Favourites, or Start Menu for quick access without installing apps or signing in again.  

There were also some major improvements with the Start menu tile theming logic. The update enabled customizations of Win32 apps on the tile background based on contrast ratio, except in the case of Microsoft Edge PWAs pinned to the background. Bug fixes were also there that fixed problems related to setting up a kiosk, resetting PC, file explorer glitches, etc. 

#7 Windows 10 Insider Preview Build 20251

Release date: November 4, 2020

The 20251 Build featured some minor bug fixes. Some fixes were for:

  • Crash with opengl32.dll.
  • Unexpected appearance of dialogs in the backgrounds
  • Settings app sending false notifications without any notification
  • Taskbar occluding the Power button in the Start menu
  • Issue causing the failure of Windows PowerShell launch for Insiders on ARM PCs. 

Some known issues with this build are an automatic DPC_WATCHDOG_VIOLATION bug check, update process hanging for prolonged periods, and non-availability of live previews for pinned sites.