What the Windows 11 KB5089573 Update Changes
The Windows 11 KB5089573 update is a system update that focuses on improving responsiveness, making system flyouts faster, app launches quicker, and core shell experiences more immediate for everyday users on both older and newer hardware. According to Windows Central’s testing, system flyouts such as the Start menu, Search, and Action Center become up to 70 percent faster, while app launches see about a 40 percent improvement. Microsoft links these gains to its internal K2 initiative, which shifts attention from new features to foundational Windows performance. KB5089573 is currently an optional preview update, so users must install it manually or enable the “Get the latest updates as soon as they’re available” toggle. The same changes will later become part of a regular security update cycle, so those who wait will still eventually receive the Windows 11 performance boost.
K2 Initiative: Fixing Windows 11’s Sluggish Feel
The KB5089573 update is the first visible result of Microsoft’s K2 initiative, a long‑term project aimed at fixing Windows 11’s reputation for sluggish responsiveness. For years, users complained that basic shell actions felt slower than earlier Windows versions, especially on low‑end machines. K2 tackles these complaints by focusing on core shell performance, moving UI elements toward WinUI 3 and cutting bloat that weighs down the interface. Microsoft’s changelog highlights accelerated app launch and faster access to Start, Search and Action Center, which are the daily touchpoints that shape how fast Windows feels. By targeting these areas first, Microsoft is addressing the most noticeable pain points instead of hiding them behind new features. Over time, K2’s broader work on WinUI 3 performance and streamlining should compound the responsiveness gains seen in KB5089573.
Inside LLP CPU Boost Mode and Why It Matters
A key part of the new responsiveness push is Windows 11’s Low Latency Profile, or LLP CPU boost mode, now starting to roll out with KB5089573. LLP briefly pushes the CPU into a higher‑performance state for one to three seconds when you trigger core shell actions, such as opening the Start menu or Notification Center. This short boost makes UI interactions feel snappier without keeping the processor at high power for long periods. Microsoft’s approach mirrors techniques already used on Android, macOS and many Linux desktops, where short bursts of CPU performance keep interfaces responsive. Some users worry that LLP CPU boost mode could hurt battery life, but the short duration and targeted triggers make that unlikely for most systems. For now, LLP focuses on shell elements; Microsoft’s roadmap suggests future updates may extend this logic to app launch speed as well.
Practical Benefits for Everyday and Low-End PCs
The combination of KB5089573 and LLP CPU boost mode directly targets everyday frustrations: slow Start menus, laggy notifications and sluggish app launch speed. On low‑end PCs, where background tasks and limited cores can cause stutter, forcing short CPU boosts during interactions helps the UI respond ahead of heavier workloads. Windows Latest observed noticeable improvements on lower‑end hardware where Windows 11 previously felt laggy. The performance gains do not exclude newer systems, though; flyouts that open faster and reduced wait times for common apps benefit anyone who spends their day jumping between tasks. Because LLP is rolling out gradually, some users will see the improvements later, and advanced users can force‑enable LLP with tools such as ViveTool. Over time, as more shell scenarios and apps use LLP, the entire desktop should feel more immediate and consistent.
Extra Quality-of-Life Tweaks Beyond Speed
While performance is the headline, KB5089573 also includes around 30 reliability and usability changes that complement the Windows 11 performance boost. Windows Hello now remains the default sign‑in for face and fingerprint users, reducing surprise fallbacks to other methods. PIN sign‑in behavior is clarified by sticking with PIN after three consecutive entries until manually changed. Clipboard history opens faster, and Windows Search can now find files with as few as two characters, which subtly improves daily workflows. Bluetooth audio sharing using Bluetooth LE Audio lets two listeners share the same PC audio, and USB4‑connected displays should wake more reliably from standby. There are also improvements to USB3 fault recovery, sensor hub power handling, and Secure Boot certificate rollout, alongside Dev Drive and Task Scheduler refinements. Together, these changes aim to make Windows 11 feel not only faster but also more predictable and convenient.