Starting with Windows 11 Insider Experimental Preview Build 26300.8935, released by Microsoft on July 20, 2026, a new screen rendering File Explorer's file properties in WinUI has been discovered. It supports dark mode and has taken on an appearance closer to other Windows 11 screens. However, what's currently working is a screen for deleted files in the Recycle Bin, and Microsoft has not announced this change in its official release notes. Rather than a finished version signaling a full replacement of the long-standing properties screen, this is a prototype—an entry point to that replacement—that has begun running on actual devices.
What Works in Build 26300.8935 Is a Single Screen for "Deleted Files"
Screenshots published on July 21 by phantomofearth, who tracks Windows changes, show the new "File Properties" displayed in a dark theme. The only tab visible is General. At the top are the file name, type, original location, and size, with the deletion date and creation date visible below that. Attributes such as Read-only, Hidden, and Archive are also present, and at the bottom are a Restore button to return the file to its original location, along with Apply, OK, and Cancel.
The target here is not regular files but rather deleted files inside the Recycle Bin. Therefore, it cannot be concluded that the various tabs in the conventional properties screen, or the screens for folders, drives, and so on, have also been replaced with WinUI. While phantomofearth suggests this may expand to other screens, this is not an announcement from Microsoft.
The File Explorer changes documented in the official release notes are separate matters: faster deletion in certain scenarios involving heavily fragmented files, improved launch and responsiveness of the Home screen, and touch-scroll support for the Recommended section. There is no mention of the new File Properties. For this reason, it should be treated not as a feature being rolled out to users, but as a screen still under development that's hidden within the build.
Build 26300.8935 is a build for the Experimental Channel, which delivers Windows 11 version 26H2 via an enablement package. Microsoft explicitly states in its description of this channel that features under testing may be changed, removed, or replaced, and may never make it outside of Windows Insiders at all. The fact that this screen is working must be kept separate from any decision to make it generally available.
File Explorer Has Been Moving to WinUI3 Piece by Piece
This prototype connects to a gradual migration Microsoft has been continuing. In 2023, the company explained that it had introduced WinUI3 into File Explorer. At the same time, it introduced the concept of "Islands"—a mechanism for incorporating WinUI3's appearance and functionality into specific parts without rebuilding the entire application. This approach allows updates to be made to targeted sections while leaving existing parts of File Explorer intact.
In the Windows quality plan presented in March 2026, Microsoft laid out a policy of moving core Windows experiences to WinUI3 to reduce operational latency and the load on the common UI foundation. For File Explorer, the company states it aims to reduce latency in search, navigation, context menus, and file operations, while improving reliability. Given that unifying appearance and improving responsiveness were placed in the same annual plan, it seems reasonable to view the new properties screen not as an isolated cosmetic touch-up, but as part of a flow of updating the Shell piece by piece.
That said, using WinUI itself does not guarantee speed. While Microsoft states that Home screen launch and certain deletion processes have become faster in Build 26300.8935, it has not presented measurements comparing the old and new properties screens. Even though dark mode support can be confirmed visually, launch time and memory usage will need to be measured individually once the implementation expands further.
Property Sheet Compatibility: A Heavier Concern Than Visual Unification
Regular file properties are not a fixed screen that's self-contained within Windows alone. According to Microsoft Learn, the Win32 Shell's IShellPropSheetExt interface calls property sheet handlers registered for each file type, allowing custom pages to be added to the default screen. The minimum supported client listed in Microsoft's documentation is Windows XP—this is an extension pathway that has been in use for a long time.
Because this mechanism exists, a full replacement requires more work than simply redrawing standard items in WinUI. Decisions need to be made about how to display pages added by existing handlers, whether to have legacy pages coexist with the new screen, and where to handle extensions that aren't compatible. The current screen for deleted files involves a relatively limited set of items and operations to display. Narrowing the scope makes it possible to trial the new UI's display and restore operation first, but this is not evidence guaranteeing that it will extend to regular files.
Functional parity presents the same issue. All that can be confirmed from the current images is the General tab and the Restore operation; whether additional tabs needed for regular files have been implemented in the new UI remains unknown. For users, what determines whether the migration succeeds is not the rounded appearance or the dark background, but whether the items they've been able to access until now, along with third-party pages, are preserved.
Conditions to Verify Before General Availability
The first point to verify is whether the new screen becomes active for regular files and folders as well. If the scope expands beyond this prototype limited to deleted files, it would make Microsoft's intent to migrate the entire property sheet considerably clearer. The second point is whether the standard additional tabs and pages registered via IShellPropSheetExt function properly. Even if the appearance is unified, the replacement isn't complete unless existing functionality and Shell extensions can still be invoked.
The third point is performance. To substantiate the latency reduction Microsoft is aiming for, launch times, responsiveness during operation, and memory usage for the old and new screens need to be compared under identical conditions. The fourth point is the delivery pathway. It's worth tracking, in order, whether Microsoft enables this screen by default in the Experimental Channel, announces it as an official change, and further expands it to other Insider Channels.
What Build 26300.8935 revealed is an early-stage prototype of moving the long-standing properties screen to WinUI. The next milestone won't be the addition of a new look—it will be the point at which regular files can be opened with existing tabs and extension pages preserved, while achieving speeds measurably equal to or better than the old screen.