KB5007651: Windows Security app update

What Microsoft.SecHealthUI does and why it can return after a feature update

On Windows 11, Windows Security is an app package, Microsoft.SecHealthUI, plus a service, SecurityHealthService, that reports protection status to it and to the notification area. The app is only the front-end: it shows and changes settings for Microsoft Defender Antivirus, Firewall & network protection, Smart App Control and Core isolation (Memory integrity), but it does not scan anything. KB5007651 replaces the app and health-service binaries and leaves the daily virus definitions (KB2267602) and the monthly Defender platform (KB4052623) untouched.

Windows 11 ships each build with its own copy of the app, and a feature update puts back the copy that belongs to that build. That copy can be older than the version Windows Update delivered under KB5007651, so Windows Update offers the same KB again afterwards. A blank or crashing app is usually a damaged registration of that package, not a protection failure.

Check the installed version or repair a blank app

Verify the installed Microsoft.SecHealthUI package version in PowerShell (or open Windows Security › Settings › About):

# Check the installed Windows Security app package version on Windows 11> Get-AppxPackage -AllUsers Microsoft.SecHealthUI | Select-Object Name, Version, InstallLocation

Check that the backing Windows Security Health service is running:

# Verify SecurityHealthService and Defender service status> Get-Service SecurityHealthService, WinDefend | Select-Object Name, Status, StartType

If the Windows Security app opens to a blank window or fails to launch after an OS upgrade, re-register its manifest from an elevated PowerShell prompt:

# Re-register the Windows Security app package (Admin PowerShell)> Get-AppxPackage -AllUsers Microsoft.SecHealthUI | ForEach-Object { Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml" }

Release history in the Microsoft Update Catalog

While Microsoft's support article text still references the May 2025 version (10.0.27840.1000), Windows Update and the Microsoft Update Catalog have shipped four newer releases under KB5007651:

For administrators (WSUS & standalone installer)

• WSUS & Configuration Manager: Classified under Definition Updates, product category Microsoft Security platform.
• Manual installation: Download the standalone installer (securityhealthsetup_*.exe for x64 or ARM64) from the Microsoft Update Catalog or support article and run it as an administrator; it installs silently in the background.