Microsoftは6月19日(現地時間)、Windows 11のWindows Insider ProgramのCanaryチャンネル向けの最新ビルド「Windows 11 Insider Preview Build 27881」をリリースしました(Windows Blog)。Canaryチャンネルで公開されるビルドは、将来の機能アップデートで追加される可能性のある、さまざまな新機能が先行して実装されています。プレビューチャンネルの中で最も不安定な可能性があり、提供されるドキュメントも限定的なものとなっています(例えば既知の不具合は掲載されないなど)。Windows Insider Programの更新オプションでCanaryチャンネルを選択し、Windows 11のプレビュー版を使用しているユーザーは、Windows Updateを利用して最新版に更新することができます。Build 27881の新機能Build 27881では、音声入力に不適切な表現フィルターのオン・オフ設定機能が追加されています。タスクバーでは注意を要するアプリを示す「needy pill」を太くして視認性が向上され、シェアウィンドウに画像の編集(トリミング、フィルター、圧縮)機能がされました。設定画面ではPCに関するFAQが「設定 > システム > 詳細情報」に追加されています。リリースノートは以下の通りです。New profanity filter setting for voice typingWe’re excited to address the top customer feedback for voice typing by starting to roll out a new setting that lets you control the profanity filter. With this setting on, voice typing will continue to filter out profanity, masking it with asterisks, like it already did. With this setting off, it will type out your profanity like any other words.To adjust this setting, open voice typing (Win + H), select the settings icon, and use the Filter profanity toggle in the settings menu.FEEDBACK: Please file feedback in Feedback Hub (WIN + F) under Input and Language > Voice Typing (Windows key plus H).Introducing speech recap in Narrator We are always working to make Narrator more intuitive, efficient, and helpful for users who rely on it every day. With that in mind, we are introducing a new feature—speech recap —designed to help you keep track of what Narrator has spoken and access it for quick reference. With speech recap, you can quickly access spoken content, follow along with live transcription, and copy what Narrator last said—all with simple keyboard shortcuts.You can open the speech recap window with Narrator key + Alt + X and can find the last 500 strings Narrator had spoken. Note that we refresh the text in this window every time Narrator starts. You can use standard reading commands and arrow keys to read the contents in speech recap window and copy text required for reference.Need to save or share something Narrator just said last? You can copy it instantly without opening the speech recap window. Use Narrator key + Control + X to copy the last spoken phrase to your clipboard.Few scenarios where you can use speech recap and related shortcuts include referring to a hint you heard when opening a new window, copying an error code that was spoken or adding Narrator speech to training materials.Live transcription of Narrator speech is useful for Assistive Technology (AT) trainers, teacher of students with visual impairments (TSVI) who support students in class and for professionals who are hard of hearing and want to use Narrator. To see live transcription of Narrator audio, use the same command Narrator key + Alt + X to open the speech recap window and snap it to the portion of the screen you want to view it. As you do tasks, you can see real-time transcriptions of Narrator speech.These keyboard shortcuts follow a simple patten making it easy to learn:Control + Windows key + Enter = Turn Narrator on/OffNarrator key + X = Re-hear what Narrator said lastNarrator key + control + X = Copy what Narrator said lastNarrator key + Alt + X = Open Speech recap window for history and live transcriptionsFEEDBACK: Please file feedback in Feedback Hub (WIN + F) under Accessibility > Narrator.Changes and Improvements[General]To stay secure and up to date, Insider Preview builds in the Canary Channel are signed with security certificates, which we renew annually. This year, we’ve made the change early. If you have a PC in the Canary Channel, we encourage you to install the latest build to avoid expiry notifications and to stay secure. Take note the new expiration is now 8/11/2026.[Taskbar & System Tray]We have adjusted the needy state pill under apps on the taskbar that need attention to be wider and more visible.We are improving Accessibility flyout in quick settings by grouping the assistive technologies by vision, hearing, motor and mobility for easy identification to help you find the right accessibility feature based on your needs. Voice access is now also included in the flyout.[Search on the Taskbar]Improved support for web search providers in Windows Search for the EEA, including with increased discoverability.[Windows Share]In the Windows share window, we are adding the ability to quickly edit and enhance images while sharing. This includes in-line image editing capabilities, such as cropping, rotating, and applying filters, as well as the ability to compress images to reduce file size for easier sharing. This ability works only for local images stored on your PC. Supported image formats: .jpg, .jpeg, .dib, .png, .tif, .tiff, and .bmp.We are adding the ability to share directly to apps that support sharing in Windows when right-clicking on local files in File Explorer or the desktop.[Settings]We’re making it easy to find answers to common questions about your PC and Windows 11 with a dedicated FAQs section on the Settings > System > About page, providing quick and helpful insights for using your PC all in one place. Whether you’re curious about system configuration, performance, or compatibility, this experience ensures you get the information you need for the frequently asked questions for those topics. We hope these FAQs will help you make informed decisions about your PC with ease.We’ve updated the dialog when renaming your printer under Settings > Bluetooth & devices > Printers & scanners to match the Windows 11 visuals.[Input]We’re trying out a small change to the design of the touch visual when dragging your finger on the screen, as part of some underlying work on rendering. The new design looks like animating bubbles. If you have a touch PC, we welcome you to try it out and share feedback under Input and Language > Touch Input and Gestures in the Feedback Hub.[Other]When running the pnputil /enum-drivers command, we’re adding a new field that enumerates driver package catalog attributes, indicating the driver type and if the driver is attestation-signed.Fixes[General]Fixed an issue for Insiders on the previous build causing some of the text in Windows to not be using the correct characters, causing nonsense to display in places like Task Manager and more. This impacted characters outside of A-Z – including Chinese and accented characters in German and Polish.Fixed an issue where booting into safe mode wasn’t working, with a message saying “Something happened and your PIN isn’t available” for some people.[File Explorer]Fixed an issue where File Explorer would crash when tapping the View button with touch.[Start menu]Fixed an issue which was causing Start menu to crash on launch for some Insiders in the last few flights.[Taskbar]Fixed an underlying issue which was causing keyboard focus to get set to widgets in the taskbar on login, which could make widgets unexpectedly invoke.Fixed an issue which could cause the media controls in the preview windows for apps in the taskbar (that support it) to flicker.Fixed an issue where when using Tab and Shift + Tab to move keyboard focus around the taskbar, if you went backwards at least once you could get keyboard focus stuck on the taskbar frame, leading some screen readers to just say “pane”.Fixed an issue where WIN + CTRL + wasn’t working to cycle between windows of open apps for that position on the taskbar.[Input]Fixed an issue where typing Japanese with the touch keyboard might stop working after switching to typing with an English keyboard and back.Fixed an issue where voice typing wouldn’t start from the touch keyboard when using the Chinese (Simplified) narrow layout.Fixed an issue where when using the Symbols section of the touch keyboard, pressing the key to change pages might unexpectedly insert a character into password fields.[Settings]Fixed an issue where you couldn’t switch active hours from manually to automatic in Windows Update.Adjusted the location of the intensity and color boost sliders under Settings > Accessibility > Color Filters, so the color previews at the top of the page are visible while adjusting the sliders.[Voice access]Fixed an issue which was causing voice access crashes when using Spanish.[Other]Fixed an issue where if you clean installed Windows using the installation media, it would unexpectedly generate an empty Windows.old folder when you were done.Made another fix for Insiders unexpectedly seeing an Administrative Templates error message when opening Group Policy Editor.Known issues[General][IMPORTANT NOTE FOR COPILOT+ PCs] If you are joining the Canary Channel on a new Copilot+ PC from the Dev Channel, Release Preview Channel or retail, you will lose Windows Hello pin and biometrics to sign into your PC with error 0xd0000225 and error message “Something went wrong, and your PIN isn’t available”. You should be able to re-create your PIN by clicking “Set up my PIN”.We’re working on the fix for an underlying issue where the taskbar is unexpectedly not showing acrylic material after upgrading to the latest Canary builds. This is impacting a few other scenarios, leading to unexpected black or white in some UI.[NEW] The “Reset this PC” option under Settings > System > Recovery will not work after upgrading to Build 27881. You can still use the “Go back” option to roll back to the previous build or download the ISO for Build 27881 here to reinstall Windows.[Settings][NEW] We’re investigating an issue in this build which may cause Settings to crash when opening microphone properties under Settings > System > Sound.公式ブログには細かな変更内容がリストアップされていますので、インストールする前に確認することをおすすめします。