Download Windows 10 KB5066791 Update Without ESU: Direct .msu Links

In October 2025, Microsoft released Windows 10 KB5066791, marking the final available update for users who have not subscribed to the Extended Security Updates (ESU) program. This particular patch addresses multiple bugs within the operating system, though it primarily focuses on improvements relevant to enterprise users. Unfortunately, individual consumers will not see any significant enhancements. The update is being distributed via Windows Update, but Microsoft also provides direct download links for those who prefer manual installation of KB5066791 (.msu) files.

Upon installing Windows 10 KB5066791, users might not notice any immediate changes. When performing an update check, the update appears as “2025-10 Cumulative Update for Windows 10 Version 22H2 for x64-based Systems (KB5066791).” Although Microsoft does not explicitly state that this is the last update available, it subtly encourages users to enroll in the Extended Security Updates program.

Overview of Windows 10 Build 19045.6456

The October 2025 update advances systems to Windows 10 Build 19045.6456. During our assessment, we discovered indications of new full-screen prompts designed to encourage users to transition from Windows 10 to Windows 11. This is a notable shift, albeit these new notifications are yet to be released widely.

Windows 10 about end of support banner | Image Courtesy: WindowsLatest.com

While Microsoft emphasizes the transition to Windows 11, it may not highlight the availability of free Extended Security Updates for Windows 10 for users with a Microsoft account. However, the focus remains heavily on promoting Windows 11 adoption, even for those considering ESU.

Obtaining Windows 10 KB5066791

You can find Windows 10 KB5066791 direct download links here: 32/64-bit | Microsoft Update Catalog.

Upon visiting the linked Update Catalog, you will find a list of items, although not all will apply to every machine. To confirm your OS edition and architecture, go to Settings > System > About. Most users will require the 64-bit (x64) version, as indicated in the screenshot below.

2025-10 Cumulative Update for Windows 10 Version 22H2 for x64-based Systems (KB5066791)

To download, select ‘Download’ next to your desired update package, and follow the prompts. Alternatively, you can use this direct link for the 64-bit/22H2 version: Update Catalog. The SHA1 for verification is: MhDSZAkb5e/7MlPQU5fE2u+6RMg=.

What’s New and Fixed in Windows 10 Build 19045.6456

This update does not introduce significant new features, which may be welcomed by some users. Among the updates detailed in the release notes, key bugs have been addressed. Notably, an issue affecting the Chinese Input Method Editor (IME) has been resolved, correcting the display of certain characters.

Additionally, the update fixes a problem with Windows Remote Management, ensuring that PowerShell Remoting functions correctly. Prior to this patch, users experienced delays of up to 600 seconds when executing PowerShell commands remotely, leading to timeouts. This has been rectified.

Comprehensive List of Fixes

A new servicing stack update has been implemented, potentially speeding up future ESUs.
Removal of tmdm64.sys, an outdated driver for older fax modem hardware.
Enhanced security measures mandating Key Storage Provider (KSP) smart card certificates, which may inadvertently cause smart card issues.

Smart Card Issues Linked to KB5066791

While not commonly used by general consumers, smart cards play a vital role in business environments for secure logins and documentation signing. However, Microsoft recently acknowledged that Windows 10 KB5066791 can result in smart card malfunctions in various applications, particularly older 32-bit programs.

Users affected by these failures will encounter error messages, such as “invalid provider type specified” or “CryptAcquireCertificatePrivateKey error.” Given that this is the last update for Windows 10, a resolution is not anticipated unless users enroll in ESU. The documentation does not suggest that Microsoft will provide a patch for this issue; instead, they have outlined a registry modification workaround:

Open Registry Editor.
Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Cryptography\Calais.
Edit the key and check for the presence of DisableCapiOverrideForRSA.
If it exists, double-click on it to set the value to 0. If not, create a new key and assign it a value of 0.
Restart your Windows system.
Your smart cards should function normally thereafter.

Upcoming Windows 10 ESU Update

For those interested in continued support, the first Windows 10 ESU security update is scheduled for release on November 11, 2025. To sign up for ESU, simply click the “Enroll now” button in the Windows Update interface, link your Microsoft account, and enable OneDrive synchronization for settings.

Windows 10 ESU enroll — How to enroll in Windows 10 ESU at no cost

If you prefer to avoid using a Microsoft account, you can purchase ESU for $29.99 through the Windows Store, which grants extended update access until October 13, 2026.

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