Microsoft's June 2026 Patch Tuesday rollout includes a quiet but significant addition for performance-focused users. Update KB5094126, now available for Windows 11 versions 24H2 and 25H2, not only patches a slew of security vulnerabilities but also activates a hidden low latency profile that measurably speeds up the Start menu and Windows Search.

Early adopters who have installed the update—which bumps build numbers to 26100.8655 on 24H2 and 26200.8655 on 25H2—report a noticeably snappier experience when launching the Start menu, typing into the search box, and navigating between UI elements. The improvement stems from a tweak to Windows' processor power management, effectively telling the CPU to ramp up responsiveness for these core shell components.

With no official documentation from Microsoft detailing the change, the feature was unearthed by Windows enthusiasts who monitor power profiles and thread scheduling behavior after each cumulative update. Their testing points to a deliberate, though undocumented, emphasis on foreground interaction latency.

A stealthy addition targeting everyday interactions

The new behavior appears to be tied to Windows' existing power management framework, specifically the "latency sensitivity hint" mechanism used by the OS to let the CPU know which processes need faster response times. By applying a more aggressive hint to Start and Search—processes hosted primarily under SearchHost.exe, StartMenuExperienceHost.exe, and the Windows Shell Experience Host—the system now treats these as high-priority UI threads that should not be starved by background tasks.

In practice, this means that even when the PC is under moderate load, the Start menu pops open with less delay, and search query suggestions appear faster. Users on a Windows Insider forum thread first noted the change after comparing dumps of their power profiles before and after applying KB5094126.

How Windows leverages low latency profiles

Windows has long offered fine-grained control over CPU frequency scaling through power plans. The built-in "High Performance" and "Ultimate Performance" plans instruct the processor to favor maximum frequency, reducing the time it takes for a core to climb from idle to a state where it can quickly process user input. However, these plans are often too aggressive for laptops, impacting battery life.

What makes KB5094126's addition interesting is that it targets only specific shell processes rather than enforcing a blanket high-performance mode. According to reverse-engineering of the update's power settings, a new CLSID-level override was added to the "Balanced" power scheme's personality. This override sets LatencySensitivityHintProcessor to a value that causes the registered processes to be treated as if they are in the "High Performance" plan even when the rest of the system remains in balanced mode.

Technical breakdown of the override

  • Affected processes: SearchHost.exe, StartMenuExperienceHost.exe, and their dependencies.
  • Power scheme: Balanced (modifications visible via powercfg /qh).
  • New setting: Processor performance increase threshold and Processor performance core parking min cores for these specific process groups have been lowered to near-zero, essentially removing scaling delays.

This selective boosting is reminiscent of how some gaming-focused utilities toggle CPU affinity and priority for game executables, but it is now baked into the operating system update itself, ensuring a consistent improvement across all machines that receive the patch.

Why Start and Search needed the boost

With Windows 11, Microsoft has heavily integrated web results and AI-powered suggestions into the search pane. The added processing overhead, combined with the fluid animations of the modern UI, can introduce perceptible lag—especially on systems running on balanced power settings. The Start menu, too, has been criticized for occasional stutter when transitioning between pinned apps and the all-apps list.

By applying a low latency profile, the CPU cores handling these interface elements receive a direct signal to climb to higher clockspeeds immediately upon user interaction. This mimics the behavior seen when an application explicitly requests "high QoS" from the operating system, but it happens transparently and without any configuration.

Security fixes bundled in KB5094126

No Patch Tuesday update would be complete without security patches, and KB5094126 is no exception. While Microsoft's release notes for this month list the typical range of fixes for remote code execution, elevation of privilege, and denial-of-service vulnerabilities, the specific CVEs addressed are embargoed until broader deployment. What is known is that the update patches critical flaws in the Windows Kernel, Graphics Component, and Secure Boot, along with a zero-day that allowed attackers to bypass SmartScreen protections via crafted .lnk files.

Organizations and individuals are urged to install the update as quickly as possible, as it addresses at least one vulnerability that has been actively exploited in the wild.

How to get KB5094126 and enable the hidden profile

The cumulative update is delivered automatically through Windows Update for all supported systems running Windows 11 24H2 and 25H2. Devices managed by WSUS or Microsoft Intune will also see the update listed as "2026-06 Cumulative Update for Windows 11."

There is no toggle or switch to control the low latency profile behavior—it is automatically applied as part of the new power settings included in the update. Users who want to verify its presence can open a PowerShell or Command Prompt window and run:

powercfg /qh

Look under the active power scheme for sub-GUID profiles related to StartMenuExperienceHost and SearchHost. The overrides will list LatencySensitivityHintProcessor keys with values set to 100 (percent) for both minimum and maximum processor state, indicating no throttling is allowed.

Compatibility note

The update is available for both x64 and ARM64 architectures, so Snapdragon-powered Windows on Arm devices also benefit from the improved shell responsiveness. Users on older Windows 11 versions (23H2 and earlier) will not receive this specific update but may see a similar change bundled into a future patch if Microsoft decides to backport it.

Early performance impressions

While no formal benchmarks have been published, enthusiastic users on several Windows forums have conducted stopwatch-based tests and shared their findings:

  • Start menu open time: On a Core i5-1240P laptop, the time from pressing the Windows key to the menu being fully interactive dropped from 540ms to 310ms after installing the update.
  • Search flyout rendering: Typing a query into the search box previously caused a brief freeze before results appeared; post-update, results populate almost synchronously with keystrokes.
  • Overall UI fluidity: Multiple users noted that context menus and taskbar interactions felt "more snappy," though this could be a placebo effect. However, the process-specific latency hints likely extend to other elements of the Windows shell that share the same hosting containers.

Battery life impact appears negligible according to testing on a Surface Laptop 6. Over a 2-hour period of mixed usage, battery drain increased by only 1-2%, likely because the profile only kicks in during active interaction rather than continuously holding clock speeds high.

The bigger picture: Windows performance evolution

This silent addition aligns with a broader Microsoft strategy to refine Windows 11's perceived performance without relying solely on hardware upgrades. Earlier efforts, such as the "Focus Assist" scheduling tweaks and the optimization of the Windows compositor, laid the groundwork. The low latency profile for Start and Search represents the next logical step: surgically improving the interactions users perform dozens of times a day.

Looking ahead, insiders familiar with upcoming Windows development builds suggest that Microsoft is experimenting with extending similar latency-sensitive hints to the File Explorer and the Settings app, which would further smooth out common friction points. If the Start and Search improvements prove successful and generate positive feedback, we may see additional shell processes receive the same treatment in future cumulative updates.

For now, the discovery in KB5094126 reinforces a trend where valuable performance enhancements are hidden beneath the surface, waiting to be uncovered by the community. As always, those who crave the snappiest experience can pair the update with the "Ultimate Performance" power plan for the broadest latency reduction, but the automatic boost to Start and Search ensures that even casual users on balanced settings will notice a difference.