Windows 11’s File Explorer Accelerates—But at What Cost?

A week ago, it was revealed that Microsoft is testing a background preloading function for File Explorer to enhance its speed. Authors at Windows Latest have already tested this feature and found some drawbacks in its operation.

Testing showed that prior to activating the feature, this Windows component consumed about 32.4 MB of RAM, based on task manager data. After activation, consumption doubled to 67.4 MB. In relative terms, this increase is substantial, but in absolute numbers, it is negligible compared to the memory capacity of modern PCs.

However, the function indeed works, though it doesn’t completely solve the problem. On a PC without other applications running, the author had to slow down screen recording four times to see a noticeable difference. But in such a mode, there is a difference: preloaded Explorer manages to close and reopen while on a PC without such a function it fully loads. If a browser with many tabs is open on the PC, the difference is noticeable even without the slowdown. Examples of videos can be viewed via the source link.

The author, however, notes that the speed still leaves much to be desired. Also, context menus on files in Explorer still appear with a noticeable delay, as the function does not cover them at all.

Additionally, the author explains why Explorer in Windows 11 opens slower than in Windows 10, even though the core of the systems is the same. In fact, both versions operate on the same Win32/COM platform (explorer.exe, shell32). Microsoft has never rewritten the core of the file management engine.

Windows 10 uses the classic Win32 interface, while Windows 11 supplements this outdated core with modern WinUI/XAML elements. From launch until the end of 2020, Windows 11 used closed XAML islands to place WinUI 2 controls within the old application. Since 2023, Explorer has begun transitioning to WinUI 3 through the Windows App SDK (WASDK). Toolbars, context menus, window titles, and areas are displayed using WinUI instead of native Win32 widgets. The combination of Win32 with WinUI/XAML introduces additional rendering layers, which is why Explorer in Windows 11 might appear slower than in Windows 10.