Microsoft has dropped Windows 11 Insider Preview Build 26120.5761 (KB5064093) into the Beta Channel for version 24H2, and the most immediately visible change is one users have begged for: dark-mode consistency for file-operation dialogs. Copy, move, delete, and access-denied prompts no longer flash blinding white when Dark mode is on—at least on the subset of devices where the server-side flag has flipped. It’s a small but meaningful polish move that reduces eye strain and makes the OS feel less broken after years of piecemeal theming.

The build, dated August 22, 2025, is a cumulative update wrapped in the enablement-series packaging that defines the 26120 branch. It continues Microsoft’s Beta Channel strategy of tight staging: some fixes and features roll out to all Insiders, while others trickle out gradually via feature flags to a hand-picked group that opted into “get the latest updates.” As a result, two machines running the exact same build number can show different UI chrome or AI capabilities—a fragmentation trade-off that Microsoft accepts in exchange for telemetry-driven safety.

What’s actually new in Build 26120.5761

Beyond the dark-mode sheen, this flight pushes forward on several Copilot-era experiments and shell reliability. Here’s the breakdown.

Dark mode finally invades legacy dialogs

The headline change targets those ancient Win32 copy/move progress windows, delete confirmations, file-in-use warnings, and access-denied prompts. Instead of stark white backgrounds, these dialogs now adopt darker grays and theme-respecting frames when the system is set to Dark mode. The improvement is controlled by a staged rollout flag, so not everyone sees it immediately. Community screenshots show that while the broad strokes are in place, some inner controls still sport mismatched styling and focus indicators remain a work in progress. Microsoft is clearly iterating rather than shipping a final coat of paint.

Click to Do gets smarter selection modes

Click to Do, the on-screen overlay for touch and pen devices, now supports Freeform, Rectangle, and Ctrl+Click multi-select modes. These let you gather mixed content—text, images, links—and apply AI actions like summarize, extract, or edit more precisely. However, the experience diverges sharply between Copilot+ certified hardware (with dedicated NPU) and standard PCs. On Copilot+ devices, many actions process on-device; elsewhere, cloud reliance can introduce latency or feature gaps. First-run initialization after a build update is noticeably sluggish, so expect a warmup period.

On-device agent inches toward natural-language settings

An on-device agent inside Settings now understands natural-language queries and can suggest or automate changes. For now, this is gated to Copilot+ AMD and Intel platforms with English as the display language. Microsoft is collecting performance and privacy telemetry during Beta, fine-tuning the model before any wider release. Enterprise managers should note this agent can alter system configurations, so group policy controls will be essential down the line.

File Explorer flirts with AI context actions

Right-click menus in File Explorer now preview AI-powered image edits: Blur Background, Erase Objects, Remove Background, Visual Search, and a Summarize option for documents (licensing-dependent). These show up conditionally and may not appear on all devices. Separately, the “Open with” dialog has been tidied—icon backplates are gone, making iconography cleaner and more legible across light and dark themes.

Snipping Tool adds window-mode recording

The Snipping Tool app—now decoupled from OS servicing—gains a window-mode recorder that captures a single app window cleanly, sizing the output to that window. This is rolling out through Microsoft Store updates, so it may arrive before or after the OS build itself.

Reliability fixes: Taskbar, Start, and File Explorer

Beta Channel builds in the 26120 series are as much about stability as new features. Fixes pushed to all users in this flight target:

  • Taskbar misbehavior: group hover animations, accidental-click mitigations, and general stability.
  • Start menu layout regressions and crashes.
  • Login/lock-screen icon rendering and lock-screen hangs.
  • File Explorer reliability issues, including context-menu bugs and dark-mode rendering glitches.
  • DWM crash reductions and overall desktop-shell robustness.

These are incremental. Microsoft acknowledges that some fixes remain under gradual rollout, so the full benefit may not materialize immediately for everyone.

Known issues: The rollback error that won’t die

No Beta build is without gremlins. Build 26120.5761 carries forward several recurring known issues that should give pause to anyone installing on a daily driver:

  • Installation rollback with error 0x80070005: A subset of Insiders see the update fail and revert. Microsoft has documented a mitigation—retry Windows Update—but root cause investigation continues. If you rely on a stable machine, validate in a VM first.
  • Xbox Bluetooth controller bugchecks: Connecting an Xbox controller via Bluetooth can crash the system. The workaround: uninstall the “XboxGameControllerDriver.inf” from Device Manager. This is a severe stability risk for gamers.
  • Click to Do instability: On first launch after a build update, Click to Do may be sluggish or non-responsive, especially on Copilot+ hardware. Give it time to initialize before judging.
  • Live Captions crash: Live translation in Live Captions can fail on some Copilot+ PCs. Accessibility-dependent users should test carefully.

These issues underscore the pre-release nature of Beta Channel software. Microsoft’s staged enablement model reduces the blast radius—only a fraction of devices see new features initially—but it doesn’t eliminate these device-specific gremlins.

The staged rollout philosophy: Why your neighbor sees what you don’t

Microsoft’s reliance on server-side feature flags is now standard operating procedure for Windows Insider builds. Rather than shipping a monolithic update that changes UI for everyone at once, the company lights up features remotely for a controlled subset. The rationale is practical:

  • Windows’ UI is a decades-old amalgam of Win32, WPF, and WinUI frameworks. A broad visual change can break accessibility tools, automation scripts, and enterprise workflows.
  • Staging allows Microsoft to gather telemetry on a manageable sample, iterate on contrast and focus indicators, and roll back quickly if needed—all without reissuing a build.
  • For features like dark-mode dialogs, Microsoft can ensure that keyboard focus rings, screen-reader semantics, and high-contrast themes aren’t regressed before scaling up.

The downside: two identical PCs can exhibit different UI chrome and AI capabilities, complicating testing for IT pros and frustrating Insiders who expect deterministic behavior. For power users, the advice is to enable the “Get the latest updates” toggle in Windows Update to increase the odds of seeing staged features.

Enterprise and IT implications

Build 26120.5761 sends several signals to enterprise teams:

  • PowerShell 2.0 deprecation and other 24H2 platform changes demand script validation now. Organizations should inventory dependencies and bundle compatibility components before broad deployment.
  • New group policy and MDM controls are emerging to manage Copilot and Copilot+ features. Expect tenant-level or device-level toggles as these features near general availability.
  • Copilot+ certification matters. Many AI agents and on-device inference features either require or perform dramatically better on hardware with high-performance NPUs. Fleets with a mix of Copilot+ and standard devices will see a bifurcated experience.
  • Operational best practices: maintain separated pilot rings, test automation and UI-dependent tools against Beta builds, and monitor Feedback Hub and Insider blog notes for critical fixes.

Deploying Beta Channel builds to production endpoints remains inadvisable. These flights are validation vehicles, not stability releases.

Accessibility: Dark mode is more than eye candy

Replacing glaring white dialogs with dark chrome has measurable benefits for visual comfort, especially in low-light environments. But Microsoft must also maintain or improve keyboard focus visibility, screen-reader semantics, and color-contrast ratios. Early tester feedback flags mismatched inner controls and inconsistent focus indicators—risks that must be closed before global enablement. Accessibility advocates should test keyboard-only navigation, high-contrast themes, and screen reader output rigorously and file repro steps in the Feedback Hub.

Practical testing tips

For Insiders who want to evaluate the dark-mode theming and AI enhancements:

  1. Confirm your build via winver or Settings > System > About. Look for the 26120 series and KB5064093.
  2. Switch to Dark mode (Settings > Personalization > Colors), then trigger file operations. If dialogs don’t respect dark theming, the flag may not be active for your device.
  3. Test Click to Do on both Copilot+ and non-Copilot hardware, noting first-run delays and feature parity.
  4. Back up data and use VMs or non-critical hardware. Avoid enabling unsupported flags (ViVeTool) on production machines.

Strengths and risks: A critical look

Strengths
- Incremental, telemetry-driven deployment reduces system-wide regressions. The staged model is pragmatic for a platform with deep legacy roots.
- Small UX polish—File Explorer icon treatments, taskbar animation smoothing—accrues into a noticeably smoother daily experience.
- AI tools like Click to Do and on-device agents are showing tangible productivity gains, especially on Copilot+ hardware with pen/touch input.

Risks
- Staged enablement fragments the user experience and complicates support for organizations needing deterministic behavior.
- Accessibility regressions remain a threat if focus indicators and contrast aren’t validated across all dialog surfaces.
- Hardware gating for AI features creates a two-tier experience that may alienate users without NPU-equipped devices.
- Severe device-specific regressions (Bluetooth controller crashes, update rollbacks) make Beta builds unfit for critical systems without thorough testing.

The bottom line

Build 26120.5761 (KB5064093) is the latest dispatch from Microsoft’s cautious, telemetry-guided refinement of Windows 11 version 24H2. It delivers genuinely welcome UI polish—dark-mode consistency in file dialogs is a quality-of-life win—alongside iterative AI enhancements and a stack of reliability fixes. But the staged rollout model means your mileage will vary, and the known issues list (especially the 0x80070005 rollback) is a reminder that Beta Channel software is still preview-grade. Enthusiasts on spare hardware should dive in; IT pros should continue treating these flights as validation builds, not deployment candidates. The dark-mode progress is real, but the last mile of polish—consistent inner controls, flawless focus rings—has yet to arrive.