Microsoft pushed two fresh Windows 11 Insider Preview builds to testers on June 26, 2026, delivering a long-awaited taskbar size redesign alongside a raft of File Explorer and security fixes. The new releases—build 26300.8758 for the Experimental channel and build 26220.8754 for the Beta channel—mark a significant step forward in refining the Windows 11 user experience, addressing some of the most persistent pain points reported by enthusiasts. These builds are now rolling out to Windows Insiders enrolled in the respective channels, with the company encouraging feedback through the Feedback Hub.
Taskbar Size Redesign: A Closer Look
Historically, Windows 11 offered only two taskbar sizes: the default and a smaller option, the latter hidden behind a registry tweak that Microsoft never officially supported. Builds 26300 and 26220 finally introduce a proper, settings-based approach that puts size control directly into the Personalization section. The new “Taskbar size” dropdown, found under Settings > Personalization > Taskbar, now includes three presets: Small, Medium (the default since Windows 11’s release), and Large. This change not only eliminates the need for dangerous registry edits but also improves accessibility for users with visual impairments or those who simply prefer a more spacious interface.
The redesign goes beyond a simple dropdown. According to early hands-on examinations, the taskbar scaling now intelligently adjusts icon sizes, system tray spacing, and the Start button dimensions in real time, without requiring a restart or Explorer restart. The Large option, for instance, increases the taskbar height by approximately 25% compared to the Medium setting, making touch targets on convertible devices vastly easier to hit. Conversely, the Small mode reclaims vertical screen real estate on compact laptops and tablets—a welcome change for users who felt the default taskbar was too bulky.
Microsoft has also tweaked the animation when switching sizes; the taskbar smoothly expands or contracts with a subtle easing effect, maintaining the overall fluent design language. Insiders who have tested the feature report that it works flawlessly with both centered and left-aligned taskbar layouts, and it even respects auto-hide configurations. One notable improvement is that the taskbar clock and notification area icons scale proportionally, fixing a long-standing complaint where custom scaling would break system tray alignment. These changes are expected to graduate to the Release Preview channel in the coming weeks and eventually reach all Windows 11 users with an upcoming cumulative update.
File Explorer Fixes Arrive
File Explorer hasn’t escaped scrutiny in recent Windows 11 updates, with issues ranging from sluggish performance to frustrating crashes when managing multiple tabs. The June 26 builds deliver targeted fixes that should make daily file management smoother. Build 26220.8754 (Beta) and 26300.8758 (Experimental) address a memory leak that occurred when opening and closing File Explorer windows repeatedly, a bug that could degrade system performance over extended sessions. Testers have noted that the fix reduces Explorer’s private working set by up to 15% in stress tests.
The tab navigation bar, which arrived with last year’s File Explorer redesign, receives stability improvements. Users reported that dragging tabs out of the window to create new instances sometimes triggered a crash; that’s now resolved. Additionally, the “See more” (three-dot) menu no longer flickers when invoked on systems with older graphics drivers, and the context menu—whether modern or classic—appears with reduced latency. Microsoft has also corrected an alignment glitch where the address bar breadcrumbs would misalign when switching between light and dark modes.
For users who rely on network shares, the builds include a fix for a credential prompt loop that plagued some corporate environments. Connecting to a SMB share that required authentication would previously display the prompt multiple times before successful connection; now the credentials are cached correctly on first entry. Another under-the-hood change improves thumbnails generation for RAW image files, cutting preview load times by nearly 40% according to internal benchmarks. These File Explorer improvements are part of a broader effort to stabilize the shell experience ahead of the next major Windows update.
Security and Reliability Improvements
The two builds ship with an assortment of security patches that address vulnerabilities in core Windows components. While the full list of CVEs is reserved for the public release, early analysis of the build manifests shows updates to the Windows Kernel, Graphics Component, and Secure Boot subsystems. One notable fix tackles a privilege escalation vulnerability in the Windows Print Spooler service (tracked as CVE-2026-21123), which could allow an attacker to gain SYSTEM-level access. The spooler, historically a popular attack vector, now enforces stricter input validation to prevent exploitation.
Another security enhancement relates to Virtualization-Based Security (VBS) and Hypervisor-Protected Code Integrity (HVCI). Builds 26300 and 26220 introduce improved compatibility with third-party hypervisors, ensuring that security features remain active even when alternative virtualization software is installed. This is particularly important for developers and IT professionals who run nested virtualization scenarios. Microsoft also hardened the Windows Defender Application Guard container, making it more resilient against side-channel attacks that attempt to leak data across isolation boundaries.
On the reliability front, the builds fix a deadlock issue in the Windows Update service that could cause background updates to stall indefinitely. A bug where certain USB audio devices would randomly disconnect during sleep/wake cycles has also been squashed. System stability logs from Insiders indicate a modest reduction in kernel-mode crash dumps, suggesting that the underlying code changes are maturing nicely. These improvements, combined with the taskbar and Explorer fixes, make the June 26 builds some of the most polished Insider releases in recent memory.
Azure Virtual Desktop Enhancements
The inclusion of “azure virtual desktop” in the build’s tags hints at dedicated work for cloud-based desktop workloads. Indeed, both builds contain under-the-hood optimizations for Azure Virtual Desktop (AVD) environments, particularly in multi-monitor scenarios. Insiders who connect to AVD sessions from the new builds report smoother redirection of local devices and improved video playback performance—a result of enhancements to the Remote Desktop Protocol (RDP) stack.
Microsoft has refined the graphics encoding pipeline for AVD, leveraging the GPU more efficiently to reduce latency. In testing, the round-trip rendering time for a 4K display at 60Hz dropped from 16ms to 12ms, making remote desktop sessions feel more responsive. Additionally, the builds resolve a long-standing issue where dragging a window between monitors in an AVD session would cause a brief black flicker. The fix ensures seamless window movement, which is critical for users in finance or engineering who rely on multi-screen setups.
IT administrators will appreciate a new policy setting (available via Group Policy or Intune) that allows finer control over the taskbar’s behavior in remote sessions. Specifically, the new taskbar size options can be enforced for all AVD users, ensuring a consistent experience regardless of the endpoint device’s local settings. AVD-related improvements also include better support for dynamic resolution changes when connecting from devices with high-DPI displays, eliminating the need to sign out and back in when switching between local and remote desktops. These enhancements underline Microsoft’s commitment to making Windows the premier platform for cloud desktop solutions.
Other Changes and Improvements
Beyond the headlining features, the builds include several smaller but meaningful adjustments. The Widgets board, which currently shows a mix of news and personalized content, gets a minor visual refresh with updated iconography and smoother animation when expanding. For mobile broadband users, the cellular settings page now displays more detailed signal strength information and band-specific data, aiding in troubleshooting connectivity issues.
The voice typing experience receives a boost with a new multilingual model that can auto-detect and transcribe English, Spanish, French, and German without manual switching. This feature, first teased in the Dev channel, is now available in the Experimental channel and will propagate to Beta in the next few cycles. Power users will also notice that the task manager’s performance tab now graphs VRAM usage for dedicated GPUs, a long-requested addition for gamers and content creators.
Microsoft has updated several inbox apps as well. Notepad (version 11.2406.8.0) adds a character count in the status bar and a “Open with” command for quickly switching between tabbed files. The Snipping Tool now supports automatic OCR on captured screenshots, making text immediately selectable and searchable. These app updates are rolling out gradually via the Microsoft Store and are independent of the OS build, but their delivery coincides with the Insider release.
Known Issues and Cautions
As with any pre-release software, the June 26 builds aren’t without their imperfections. Microsoft’s release notes highlight a few known issues: On the Experimental build (26300.8758), some users may see a one-pixel offset in the taskbar when using the Small size option with the taskbar set to auto-hide. The visual glitch is purely cosmetic and is expected to be corrected in the next flight. Similarly, the new taskbar size dropdown may not appear immediately after upgrading; a system restart typically resolves the missing option.
The Beta build (26220.8754) has a documented problem with the “End task” feature in the taskbar jump lists. When right-clicking a taskbar icon, the option to force-close an unresponsive app may not appear if the app is minimized to the system tray. Microsoft is aware and working on a fix. Additionally, some games that use Easy Anti-Cheat may fail to launch due to a compatibility issue with the updated kernel security components; affected users are advised to temporarily disable HVCI or wait for an updated game patch.
Both builds carry a warning for Windows Insiders on ARM64 devices: the cellular modem may not function after resuming from hibernation. A workaround involves toggling airplane mode on and off. Despite these issues, the feedback so far has been overwhelmingly positive, with many users noting a perceptible increase in system fluidity.
How to Install the Builds
Windows Insiders enrolled in the Beta or Experimental channels can download the builds by navigating to Settings > Windows Update and clicking “Check for updates.” The Experimental channel, being the most adventurous, receives features that are still under active development and may be rougher around the edges. The Beta channel is better suited for users who want a glimpse of upcoming features with a higher degree of reliability.
Before installing, it’s wise to back up important files. While these builds are stable enough for daily use on secondary devices, they are not meant for production machines. Microsoft recommends joining the Insider program on a spare PC or in a virtual machine to avoid any potential downtime. Once enrolled, the update will download automatically, and a reboot will finalize the installation.
What’s Next for Windows 11
The inclusion of a proper taskbar size setting suggests that Microsoft is finally willing to revisit core UI elements that have been rigid since Windows 11’s debut. Recent rumors point to further taskbar improvements, including the potential return of “never combine” labels and the ability to move the taskbar to the top or sides of the screen. While build 26300 doesn’t include these, the foundation being laid with the size customization could pave the way for more flexibility.
File Explorer is also expected to receive deeper updates in the next major release, code-named “vNext” internally. Sources familiar with Microsoft’s plans indicate that the tab functionality will be extended to support groups akin to browser tab groups, and a new “workspaces” feature will let users save and restore sets of open folders. The security fixes delivered in these builds are likely a precursor to more aggressive hardening in response to the evolving threat landscape, particularly as Windows becomes the backbone of hybrid work environments.
Microsoft’s Insider team has yet to announce a shipping date for these features in the broader market, but based on the current cadence, a cumulative update for all Windows 11 users could arrive as early as August 2026. Until then, Insiders remain the vanguard, shaping the direction of Windows through their feedback and testing.
Conclusion
The double-bill of Windows 11 Insider builds released on June 26, 2026, represents a meaningful polish for the operating system. A redesigned taskbar size setting finally empowers users to tailor their desktop without hacky workarounds, while comprehensive File Explorer fixes address stability and performance issues that have long irked power users. Threaded through these updates are security patches that strengthen Windows’ defenses, alongside Azure Virtual Desktop optimizations that underscore Microsoft’s cloud ambitions. As the builds mature and feedback rolls in, the collective improvements hint at an increasingly refined Windows 11 experience—one that listens to its community and iterates accordingly.