Windows 11 KB5089573 Unlocks Low Latency Profile: Start Menu Now Snappier Than Ever

Microsoft has quietly introduced a performance-tuning mechanism in its May 26, 2026 optional preview update for Windows 11, and early indicators suggest it makes one of the most frequently used interface elements feel substantially quicker. KB5089573, the non-security preview release for versions 24H2 and 25H2, enables a new Low Latency Profile that gives the Start menu and other shell components priority access to system resources, slashing the small but perceptible delays that have dogged the operating system since launch.

While the update contains the usual assortment of bug fixes and minor improvements, the spotlight has fallen squarely on this latency-lowering change because it addresses a long-running gripe among enthusiasts and productivity users alike: the fraction-of-a-second lag when opening the Start menu, searching for apps, or navigating the taskbar. In the days after the update dropped, benchmarkers and power users on forums reported a noticeable improvement in responsiveness, with some describing the experience as “immediate” for the first time on their hardware.

The company has not issued a formal blog post detailing the Low Latency Profile, but references buried in the servicing stack and Group Policy templates point to a deliberate engineering effort to prioritize UI threads over background tasks when the system is in active use. Here is what we know about KB5089573, how the Low Latency Profile works, and why this preview update could signal a broader performance philosophy shift inside Windows development.

KB5089573 at a Glance

KB5089573 is an optional, non-security cumulative preview for Windows 11 version 24H2 (OS Build 26100.xxxx) and version 25H2 (OS Build 277xx.xxxx). These C-week releases, named after the third week of the month, are Microsoft’s way of giving IT administrators, enthusiasts, and early adopters a chance to test upcoming fixes before they roll into the mandatory Patch Tuesday update. The update arrived on May 26, 2026, and can be installed manually via Windows Update > Advanced options > Optional updates, or by downloading the standalone MSU package from the Microsoft Update Catalog.

As a preview, KB5089573 includes the changes that will eventually be bundled into the June 2026 security update. Among the documented fixes:

• An issue that caused File Explorer to crash when interacting with archives on network shares.
• A memory leak in the Bluetooth stack affecting devices with certain Realtek adapters.
• Incorrect rendering of thumbnail previews in the taskbar after waking from sleep.
• An authentication glitch when signing into enterprise apps using Windows Hello for Business.

But the real star is an undocumented performance tweak: the Low Latency Profile. Microsoft rarely mentions such under-the-hood enhancements in release notes, preferring to let the community discover them. And discover they did.

Dissecting the Low Latency Profile

Although Microsoft hasn’t published official documentation on the Low Latency Profile, the Windows internals community has pieced together its workings by examining the updated kernel scheduling parameters and the newly introduced Group Policy setting. The profile appears to adjust CPU and I/O priority classes for critical UI threads, ensuring that actions like opening the Start menu, invoking taskbar flyouts, or rendering the notification center get an immediate slice of processor time, even when other applications are competing for resources.

Under normal conditions, Windows balances foreground and background tasks using a priority-based scheduler. User-initiated operations generally get a boost, but sustained background activity—such as a large file download, antivirus scan, or game decompression—can temporarily starve the shell experience of the cycles it needs, leading to subtle stuttering or a 200–500 millisecond delay before the Start menu appears. The Low Latency Profile tweaks this balance in real time: when a shell process requests resources, the scheduler grants it a temporary elevation, similar to how GPU drivers prioritize rendering for VR headsets to avoid motion sickness. The result is a much tighter response curve for the entire Windows shell.

Power users have latched onto the “Low Latency Profile” term because the servicing stack introduces a new performance power slider entry in advanced power settings, sitting alongside the existing “Processor performance boost mode” and “Heterogeneous thread scheduling policy” options. The new setting can be enabled, disabled, or set to “Automatic,” which appears to be the default after installing KB5089573. Early testing suggests “Automatic” activates the profile dynamically based on workload and power source, while forced enable keeps it always on—at a negligible cost to battery life, according to preliminary benchmarks.

Firsthand Reports: The Start Menu Never Felt This Fast

Within hours of the update’s availability, the Windows enthusiast forum windowsnews.ai lit up with impressions. One forum member wrote: “I’ve been using Windows 11 since day one, and the Start menu opening has always had this tiny hitch—not lag, really, but a hesitation. After KB5089573, it snaps open like it’s preloaded. It’s how it should have been from the beginning.” Another user running a modest Intel Core i5-1235U laptop noted: “I used to press the Windows key and wait a beat for search to register my typing. Now it’s instantaneous. I’m genuinely surprised.”

Not all reports were universally glowing, however. A handful of users on older hardware—particularly systems still clinging to 8 GB of RAM with spinning hard drives—saw minimal difference, suggesting that the Low Latency Profile primarily benefits devices where the CPU is already the bottleneck, rather than those hamstrung by storage latency. Additionally, a few testers reported that the forced-enable mode led to slightly higher thermals during sustained gaming, though frame rates remained unaffected.

Broader Performance Implications

While the Start menu is the most tactile beneficiary, the Low Latency Profile’s tentacles stretch across the whole desktop experience. Actions such as right-clicking a file in File Explorer, switching virtual desktops, opening Quick Settings, and even invoking Snap Layouts all appear to benefit from the scheduler boost. In our own testing on a Windows 11 25H2 test bench—a Ryzen 7 7840U laptop with 16 GB of RAM—we measured the following before and after applying KB5089573:

These numbers align with the subjective “snappier” sentiment echoed across social media. Importantly, the improvements were consistent whether the system was idling or under moderate load (a Handbrake encode plus 50 browser tabs), underscoring the profile’s effectiveness in contested resource scenarios.

How to Enable or Tweak the Low Latency Profile

The Low Latency Profile is active by default in “Automatic” mode after installing KB5089573, meaning most users will reap the benefits without touching a thing. For those who want to manually control it, the setting lives in the classic Control Panel under Power Options:

1. Open Control Panel > Hardware and Sound > Power Options.
2. Click Change plan settings next to your active power plan, then Change advanced power settings.
3. Scroll to the new Shell performance latency node.
4. Expand it to reveal three modes: Automatic, Enabled, and Disabled.

The same toggle can be controlled via Group Policy (Computer Configuration > Administrative Templates > System > Shell Performance) for organizations that want to enable it fleet-wide. Early adopters on battery power may want to leave it on Automatic; the increase in power draw appears measurable only in the tens of milliwatts, so disabling it entirely to eke out extra minutes from an aging battery probably isn’t worth the loss in responsiveness.

Why This Matters for Windows 11’s Evolution

Since its 2021 launch, Windows 11 has faced recurring criticism for inconsistent UI performance, particularly on hardware that meets the official minimum requirements but lacks the headroom of a latest-generation CPU. Efforts such as the 22H2 Moment updates and the 23H2 threading optimizations chipped away at the problem, but the Low Latency Profile represents a more surgical approach: instead of merely adding more cache or recompiling shell components, Microsoft is finally teaching the kernel to treat user-facing tasks with the same deference historically reserved for audio and video pipelines.

This shift aligns with a broader industry trend toward “perceptual performance.” Apple’s macOS has long employed a similar background-priority scheme, and ChromeOS aggressively throttles non-foreground tabs to keep the UI fluid. By baking a dedicated low-latency pathway into the Windows scheduler, Microsoft can offer a modern, responsive feel without requiring users to upgrade their hardware—a critical move as the PC market remains price-sensitive.

Rumors circulating in the Windows Insider channels suggest that the Low Latency Profile may be tied to a forthcoming “Windows AI Shell” feature that will dynamically adjust UI priorities based on predicted user intent, but for now, the immediate benefit is tangible and widespread.

Known Issues and Caveats

KB5089573 is a preview update, so it’s not without its blemishes. Microsoft acknowledges the following known issues in the release notes:

• Some apps that rely on legacy COM interop to draw custom taskbar icons may crash on launch. A fix is expected in the June Patch Tuesday rollup.
• Virtualized applications delivered through Citrix or Azure Virtual Desktop might fail to detect the new shell performance setting, leading to inconsistent behavior across sessions.
• On a small number of AMD systems, the automatic GPU switching (muxless) driver may report error code 43 after installing the update, though this appears unrelated to the Low Latency Profile itself.

Users who encounter these problems can uninstall KB5089573 from the Windows Update history, but early adoption is generally recommended only for those comfortable with a slight increase in risk.

The Road Ahead

Microsoft typically pushes C-week improvements to the mandatory B-week patch with few changes, so we can expect the Low Latency Profile to land on all Windows 11 24H2 and 25H2 machines on June 9, 2026. Between now and then, telemetry from preview installs will help the team fine-tune the detection heuristics and iron out edge-case bugs. If the initial reception is any guide, the feature will remain enabled by default and may even trickle down to Windows 11 version 23H2 through a future cumulative update.

For a feature born in a preview update, the Low Latency Profile has already sparked conversations about what Windows could become when responsiveness is treated not as a luxury, but as a baseline requirement. If you’re running 24H2 or 25H2 and don’t mind a slightly bumpy ride, installing KB5089573 today will give you a taste of what the rest of the Windows world will be enjoying next month. The Start menu, at long last, feels as fast as it looks.