Microsoft released an optional preview update on June 23, 2026 that targets one of the most persistent complaints among Windows 11 users: File Explorer launch times and overall responsiveness. The KB5095093 update rolls out to systems running Windows 11 versions 24H2 and 25H2, advancing the OS builds to 26100.8737 and 2620, respectively. The patch arrives via Windows Update as a preview, meaning administrators must proactively opt in to install it. Early testers report that the improvement is immediately noticeable, with File Explorer windows appearing almost instantaneously after the update.
A Long-Standing Grievance
File Explorer has been the default file management tool in Windows for decades, but its performance has come under increased scrutiny since the release of Windows 11. Users on forums and social media have regularly documented sluggish behavior—windows taking several seconds to populate, right-click context menus freezing, and the navigation pane struggling to keep pace with user input. Microsoft has incrementally addressed these issues in cumulative updates throughout 2025 and early 2026, but KB5095093 represents the most focused effort yet to tackle launch speed.
Performance regressions in File Explorer often stem from deeper changes in Windows 11’s architecture. The modernized context menu, integration with OneDrive, and the need to enumerate cloud-backed files all add overhead. Moreover, the transition to the WinUI framework for parts of the shell introduced new threading models that, when mishandled, caused UI hangs. Microsoft’s changelog for KB5095093 is concise but explicit: “This update optimizes the initialization sequence of File Explorer, reducing the time required to render the window and display contents after launch.”
What KB5095093 Changes
KB5095093 is classified as a non-security, quality update. It does not introduce new features but rather refines existing code paths. The update packages for both 24H2 and 25H2 weigh in at approximately 450 MB on x64 systems, suggesting a significant number of binary replacements. Key components receiving attention include explorer.exe, several shell extension DLLs, and the Windows.UI.FileExplorer runtime class used by the modern file management interface.
Build 26100.8737 for Windows 11 24H2 and build 2620 for 25H2 include fixes that restructure how File Explorer preloads shell extensions. Historically, third-party extensions—such as cloud storage overlays or compression tools—could block the main thread during startup. The update introduces a staggered loading scheme for non-Microsoft extensions, ensuring the core window becomes interactive before optional add-ons finish loading. This alone accounts for the most dramatic reduction in visible launch delay.
Additionally, Microsoft has tuned the rendering pipeline for the tabbed interface introduced in Moment 1. File Explorer now defers the drawing of inactive tabs until they are selected, cutting CPU and GPU usage at startup. The address bar and command bar also benefit from same-frame compilation, eliminating a flicker that some users observed when launching Explorer on high-DPI displays.
Availability and Installation
The June 23 preview is optional, meaning it will not install automatically unless the user explicitly selects it. To download KB5095093, navigate to Settings > Windows Update > Check for updates, then click Download and install under the “Optional quality update available” section. Enterprise environments can deploy it via Windows Server Update Services (WSUS) or Microsoft Endpoint Configuration Manager by importing the appropriate MSU file from the Microsoft Update Catalog.
As with any preview update, mainstream users may want to wait for the July Patch Tuesday rollout, where these improvements are expected to be bundled into the mandatory cumulative update. However, the risk profile is low: KB5095093 has been in internal testing since early June and comes with no known issues listed in Microsoft’s release health dashboard. The update is applicable to all editions of Windows 11 24H2 and 25H2, including Home, Pro, Enterprise, and Education.
Performance Benchmarks: What Users Are Seeing
Although Microsoft has not published official metrics, early adopters have shared their experiences. In controlled tests on a Dell XPS 15 (Intel Core i7-13700H, 16 GB RAM, NVMe SSD) running build 26100.8737, cold-launch times—measured from click to a fully rendered window with Quick Access content loaded—dropped from an average of 1.8 seconds to under 400 milliseconds. Warm launches (Explorer already cached in memory) became near-instantaneous at around 100 milliseconds.
More importantly, the perceived responsiveness has improved. Users who consistently saw a spinning cursor when opening folders with many images or videos report that the delay is largely gone. One IT administrator on the Windows Insider forums noted, “The difference is night and day. I deployed KB5095093 to a pilot group, and we’ve had zero reports of Explorer hanging since.”
The Historical Context of File Explorer Overhauls
File Explorer performance has been a recurring theme in Windows development. Windows 11’s original release in 2021 introduced a redesigned command bar and context menus, but many users complained that the new visuals came at the cost of speed. Microsoft responded by making the classic context menu accessible via Shift+Right-click and later restored drag-and-drop functionality to the taskbar. In 2024, a major refactor of the navigation pane database improved folder enumeration times, but launch speed remained a sore point.
The 24H2 update from late 2025 brought architectural changes that laid the groundwork for today’s optimizations. Separating the file indexing service from the main Explorer process allowed for asynchronous updates, but the full benefit was only realized once the launch sequence was restructured. KB5095093 is the culmination of that multi-year effort.
What About Windows 11 25H2?
For users on the newest feature update—Windows 11 25H2, build 2620—this update carries special significance. 25H2 introduced an updated file system filter driver that improves compatibility with ReFS volumes, but early builds experienced intermittent crashes when launching File Explorer on systems with older storage drivers. KB5095093 includes a fix for that regression, making it a vital stability update for those on the bleeding edge.
The 25H2 build number 2620 represents an incremental jump from the 26200.x preview builds that shipped earlier in the year. Microsoft has not disclosed the exact minor build string (e.g., 2620.xxxx), but the release branch aligns with the June preview ring timeline. Insiders in the Dev Channel who had already moved to 2620 received a smaller delta patch to incorporate the Explorer improvements.
Expert Analysis: Under-the-Hood Improvements
Several technical changes contribute to the speedup. First, Microsoft has migrated parts of the Explorer initialization logic from C++/COM to Rust, a systems programming language that offers memory safety and zero-cost abstractions. The new Rust modules handle the parsing of folder views, icon extraction, and thumbnail generation—tasks that previously relied on decades-old code rife with potential for thread contention.
Second, the update tweaks the process model for explorer.exe. In previous builds, a single main thread handled both window message processing and shell namespace walks. Now, namespace enumeration runs on a background thread pool with a higher priority, ensuring that the window becomes visible and responsive even if the enumeration takes longer. This aligns with the asynchronous patterns already used by modern UWP applications.
Finally, the shell extension host (ExplorerHost.exe) has been given a higher GPU priority, reducing the time required to render the acrylic blur effects and icon animations. For systems with dedicated GPUs, this means the visual polish no longer comes at the expense of input responsiveness.
Potential Pitfalls and Remaining Issues
No update is flawless, and KB5095093 may cause side effects for a small percentage of users. Early feedback suggests that some third-party shell extensions—particularly those that inject custom buttons into the toolbar—may fail to load under the new staggered initialization scheme. Developers of tools like 7-Zip and Directory Opus are already working on updates to comply with the new loading rules.
Another reported quirk involves the Quick Access pinning feature. On systems with extremely large Quick Access lists (tens of items), the first launch after installing the update may still take up to a second as the database is rebuilt. Subsequent launches revert to the expected fast times.
Microsoft has published a known issue for Windows 11 24H2 devices with certain Intel SST audio drivers, but that is unrelated to File Explorer and predates KB5095093. Users who experience any regressions should file feedback via the Feedback Hub under the Desktop Environment > File Explorer category.
How KB5095093 Fits into the Broader Update Cadence
Preview updates like KB5095093 have become a regular fixture of Microsoft’s servicing strategy. Released in the fourth week of every month, these non-security updates allow organizations and enthusiasts to validate fixes ahead of the mandatory Patch Tuesday rollout. For June 2026, this preview also coincides with the end of support for Microsoft’s legacy EdgeHTML engine, though that change is separate.
The inclusion of File Explorer optimizations in a quality update—rather than waiting for a feature update—signals a shift in how Microsoft prioritizes performance work. Rather than holding improvements for an annual feature drop, the Windows servicing team now treats user-perceived performance regressions with the same urgency as security vulnerabilities. This agile approach has been praised by the Windows community, as it delivers tangible benefits without the wait.
What Comes Next
Microsoft’s internal roadmap hints at further Explorer enhancements later in 2026. The Most Valuable Product (MVP) community has discussed upcoming API changes that will allow cloud storage providers to integrate more efficiently, reducing the performance penalty of syncing directories. Additionally, the legacy Control Panel is gradually being replaced by the Settings app, which may eventually lessen Explorer’s burden by offloading some management tasks.
For now, KB5095093 stands as a welcome shot in the arm for Windows 11’s desktop experience. With File Explorer at the heart of daily workflows, every millisecond shaved off its launch time compounds into regained focus and productivity throughout the day. Users on 24H2 and 25H2 are encouraged to grab the optional update if they haven’t already, keeping in mind that a shadow backup rolls out with July’s mandatory update.
Final Verdict
KB5095093 is more than a routine maintenance patch—it’s a demonstration that Microsoft is listening to the feedback that has dogged Windows 11 since its inception. By zeroing in on the moment-to-moment interactions that define the operating system’s feel, the development team has delivered an update that makes the entire platform feel lighter and more responsive. In an era where hardware is faster than ever, it’s refreshing to see software finally keeping pace.