Windows 10 build 21370 is now available with Bluetooth audio improvements

Microsoft missed its typical Wednesday schedule for a new Windows 10 build release in the Dev channel, instead giving us another pipeline test update. We're still getting a new build this week, though, as Microsoft is now rolling out build 21370 from the co_release branch.

This build is a bit lighter on features than last week's release, but it does pack a significant improvement for anyone who uses Bluetooth earbuds or headphones on Windows 10. Now, users will see a unified endpoint for a Bluetooth device, instead of seeing two different items. These two items were used to distinguish between a speaker-only channel, which offered better audio quality but no microphone input, and another channel meant for communications, which enables the microphone but offers worse audio quality. Now, only a single item will be chosen, and Windows automatically switches between them. Another improvement for Bluetooth audio is support for AAC codecs, which should offer better audio quality.

Aside from that addition, there are a handful of smaller changes in this build, including some tweaked icons in File Explorer. Here's the full list:

• We’ve made some small adjustments to the icons in File Explorer’s address bar.
• We’ve improved the touch keyboard launch animation to make it smoother in cases where UWP apps reflow when it appears.
• We made a change so that if you set focus to the Run dialog, the touch keyboard will now show a backslash (\) key.

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

• [News and interests] We fixed an issue where hovering over the news and interests button sometimes may not open the flyout.
• [News and interests] We fixed an issue where the news and interests flyout may get stuck displaying the loading spinning dots.
• [News and interests] We made some explorer.exe reliability and performance improvements.
• [News and interests] We fixed an issue where news and interests may sometimes briefly appear on the taskbar if the taskbar is aligned to the top.
• We fixed an issue resulting in some Insiders seeing error 0x80092004 when installing KB5001030 – 2021-02 Cumulative Update Preview for .NET Framework 3.5 and 4.8 after updating to the previous build.
• We fixed an issue that could result in Insiders seeing error 0x80070005 when installing framework updates.
• We fixed an explorer.exe crash in the previous flight that could result in issues with the login screen and logging in after resuming from sleep.
• We fixed an issue resulting in some Insiders experiencing bugchecks with a CRITICAL PROCESS DIED error.
• We fixed an issue where Narrator wasn’t announcing the error message on the login screen after entering the wrong password multiple times.
• We fixed an issue resulting in broken characters appearing in text across Settings.
• We fixed an issue in the last couple flights resulting in Cortana not launching from the taskbar after clicking the icon.
• We fixed an issue impacting mouse input on the dual boot screen.
• We fixed translation issues in the –help text in the Windows Subsystem for Linux.
• We fixed OS upgrades creating copies of libdxcore.so and other files when using the Windows Subsystem for Linux.
• We fixed two issues impacting conhost.exe reliability.
• We fixed two issues preventing some USB printer drivers from initializing correctly.
• We fixed an issue where if you sent the VK_HOME virtual key code while the Japanese IME was active and numlock was on, unexpected 7 would be input.
• We fixed an issue where the Japanese 50-on touch keyboard layout wasn’t inserting full-width space characters correctly when it was in the Shift state.
• We fixed an issue where the Chinese Pinyin IME was inserting a placeholder string if you selected a cloud candidate while the cloud candidate entry was still loading.

Finally, there are still some known issues, though this list has shrunken significantly with the past few releases. Here's what you need to look out for:

• We’re looking into reports of the update process hanging for extended periods of time when attempting to install a new build.
• We’re investigating an issue where elements of Search (including the search box in File Explorer) are no longer displaying correctly in dark theme.
• The Windows Camera App currently does not respect the default brightness setting set via the new Camera Settings page.
• We’re working on a fix resulting in WSL users finding that File Explorer launch performance regressed after upgrading to Build 21354 and higher.
• Some Windows Subsystem for Linux instances can fail to launch with a ‘The parameter is incorrect’ message. This known issue is being tracked here on the WSL repository.

The update will show up for you and install automatically if you're in the Dev channel. It's still unclear when exactly the features in these builds will be making their way to the general public, since Dev channel builds aren't tied to the next major Windows 10 update. However, it's likely we'll get a new feature update in the second half of the year, which should include at least some of these changes. In the meantime, Microsoft recently announced the May 2021 Update, which is just an enablement package for the previous version of Windows 10 with a few improvements.