[UPDATE: New Build] KB5070311 Adds Virtual Workspaces to Advanced Settings & Consistent Dark Mode in File Explorer

[UPDATE 11/26] Microsoft has released Builds 26100.7309 and 26200.7309 under the same KB5070311 for Windows 11 version 24H2 and 25H2, with “some minor changes.”

[ORIGINAL] Microsoft is rolling out KB5070311 as part of its latest Windows 11 update. After updating your Windows 11 systems on version 24H2 and 25H2, you’ll see a new, dedicated Virtual Workspaces section under Settings > System > Advanced. This page lets you enable or disable virtual environments such as Hyper-V, Windows Sandbox, and other isolated workspaces.

Microsoft says the feature is rolling out gradually, and availability will vary by device and market. Some users may not see the option immediately, especially on hardware that does not support virtualization.

Moving on, the update also fixes an issue where users could see STATUS_NOT_SUPPORTED (0xc00000bb) errors during login when using ECC Smart Card Logon Credential. The bug caused authentication failures on some systems.

Besides this, Microsoft also confirmed that KB5070311 fixes a stability issue that affects the Local Security Authority Subsystem Service (LSASS). An access violation could make LSASS unstable, potentially leading to reliability problems.

Last but not least, File Explorer in Windows 11 now offers a more consistent dark mode experience. Key dialogs for copy, move, and delete actions have been updated, and progress bars and charts match the dark theme. Confirmation dialogs and error messages have been updated to match the dark theme, alongside consolidated share options. Thumbnails for certain videos are also fixed.

Microsoft has also fixed a few known issues in File Explorer. Thumbnails for video files with certain EXIF metadata now appear correctly. An old white toolbar that sometimes appeared randomly has been fixed. Moreover, right-click file icons now correctly match the default app instead of showing generic icons.