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Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Out-of-band update
Out-of-band

KB5066188

KB5066188: Cumulative update for Windows 10, versions 21H2 and 22H2, August 2025. Reset and recovery failures addressed

In short

Addresses failures when resetting or recovering Windows 10 devices introduced by the August security update. Install it if you encountered the problem or plan to use the affected recovery methods.

Does it affect you? Applies to: Devices running Windows 10, version 22H2, and Windows 10, version 21H2 on Enterprise LTSC 2021 or IoT Enterprise LTSC 2021.

Builds
19044.6218 · 19045.6218
Restart
Required
Review notes Additional details from the official release notes (4) Read notes
  • In short Microsoft recommends this optional update if you have encountered the reset-and-recovery issue. If your system is unaffected or you do not plan to use the listed methods, you can choose not to install it.
  • What to do Microsoft recommends this optional update if you have encountered the reset-and-recovery issue. If your system is unaffected or you do not plan to use the listed methods, you can choose not to install it.
  • In detail Windows 10 Enterprise LTSC 2021 support ends January 12, 2027, and Windows 10 IoT Enterprise LTSC 2021 support ends January 13, 2032.
  • In detail Secure Boot certificates used by most Windows devices started expiring in June 2026. Microsoft advises reviewing its guidance and updating certificates in advance to avoid disruption.

The official sources are linked at the end of the page.

What changes

Fixes 2 changes

Reset and recovery

2 items
  • Addresses failures when resetting or recovering a Windows 10 version 21H2 device using the listed recovery methods.1
    For Windows 10 Enterprise LTSC 2021 and IoT Enterprise LTSC 2021. The affected methods include Reset my PC, Fix problems using Windows Update, and RemoteWipe CSP.
  • Addresses failures when resetting or recovering a Windows 10 version 22H2 device using the listed recovery methods.1
    The affected methods include Reset my PC, Fix problems using Windows Update, and RemoteWipe CSP.

Improvement 1 change

Servicing stack

  • The component that installs Windows updates receives quality improvements.2
    Includes the Windows 10 servicing stack update KB5063261.

Known issues

  1. Resolved Affects: Everyone Resolved by KB5065429

    Network Device Interface streaming performance issue

    After the August 2025 security update, NDI streaming might have delays or uneven audio and video, especially with OBS Studio or NDI Tools when Display Capture is enabled on the source PC. Windows updates released on and after September 9, 2025, including KB5065429, resolve this issue.3

    Resolution Fixed in KB5065429

    Install KB5065429 (or a later cumulative update) on affected devices. No manual workaround is required after updating.

  2. Resolved Affects: Everyone Resolved by KB5065429

    Unexpected User Account Control (UAC) prompt when doing MSI repair operations

    After the update, standard users might see a UAC prompt during MSI repair and related operations; some operations without a prompt might fail. Windows updates released on and after September 9, 2025, including KB5065429, resolve this issue.4

    Resolution Fixed in KB5065429

    Install KB5065429 (or a later cumulative update) on affected devices. No manual workaround is required after updating.

Technical details

Data sheet · Security · Downloads · Components Click to collapse or expand

Data sheet

Released
2025-08-19
Classification
Updates
Type
Cumulative update
Restart
Required
Replaces
KB5063709, KB5062649, KB5062554, KB5061087
+20 earlier KB5063159, KB5060533, KB5058481, KB5061979, KB5061768, KB5055612, KB5053643, KB5052077, KB5050081, KB5046714, KB5045594, KB5043131, KB5041582, KB5040525, KB5039299, KB5037849, KB5036979, KB5035941, KB5034843, KB5034203
Replaced by
KB5065429
VersionBuildChannel
21H2 19044.6218 General availability
22H2 19045.6218 General availability

Security

No vulnerabilities are listed for this update.

Updated components

255 files changed since the previous update for the same versions.

Top changed componentsFiles
Kernel3
Secure Boot3
Hyper-V and virtualization2

Sources

Updated
Cited passages from Microsoft's official notes (4)
  1. 1. This update addresses an issue introduced by the August 2025 security update (KB5063709) in which attempts to reset and recover the device fails. support.microsoft.com
  2. 2. This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. support.microsoft.com
  3. 3. This issue is resolved by Windows updates released on and after September 9, 2025 (KB5065429). support.microsoft.com
  4. 4. This issue is resolved by Windows updates released on and after September 9, 2025 (KB5065429). support.microsoft.com
Checked automatically: 8 of 8 checks passed, 4 quoted passages · compared with Microsoft's page on Oct 20, 2026
  • Quotes found in the official pages: passed
  • Numbers found in the sources: passed
  • Vulnerabilities from the dossier only: passed
  • Links to allowed domains only: passed
  • Every official change covered: passed
  • Readable plain text: passed
  • Changes confirmed by the file list: passed
  • Sources agree: passed

A second AI read the text against the sources: correctness 3/5, clarity 4/5, completeness 3/5. How we work

Published by The Update Bureau. Written with AI from Microsoft's own documents, checked by rules and a second AI. How we work · Report a mistake