Key Changes & What’s New:
- Security Fixes: Patches 114 vulnerabilities, including a zero-day flaw in Agere modem drivers and a bug where security software flagged WinSqlite3.dll as vulnerable.
- Secure Boot Certificate Updates: Includes data that enables devices to automatically receive new certificates to ensure Secure Boot continues to function securely.
- Driver Removal: Removes specific legacy modem drivers (agrsm64.sys, agrsm.sys, smserl64.sys, smserial.sys) that can prevent dependent hardware from working.
- Build Number: Updates Windows 10 to OS Build 19045.6809 (or 19044.6809 for LTSC).
- ESU Program: Primarily for Windows 10 Enterprise LTSC or ESU-enrolled devices, mandatory for security.
Microsoft has released KB5073724, the Windows 10 Extended Security Update (ESU), since the operating system’s official support ended on October 14, 2025. This update is exclusively available to devices enrolled in the ESU program and upgrades.
- Windows 10 version 22H2 to build 19045.6809
- Windows 10 Enterprise LTSC 2021 to build 19044.6809
The most notable change in this update involves the removal of legacy modem drivers, specifically agrsm64.sys (x64), agrsm.sys (x86), smserl64.sys (x64), and smserial.sys (x86), which will no longer function on systems after the update.
The update also addresses the upcoming expiration of Secure Boot certificates by introducing a phased deployment mechanism. Starting with today’s update, Windows quality updates include high-confidence device targeting data to identify eligible devices that automatically receive new Secure Boot certificates.
Windows 10 KB5073724 also includes fixes for three actively exploited zero-day vulnerabilities, one of which is an elevation of privilege flaw in the built-in Agere modem drivers. A security flaw in the third-party WinSqlite DLL has also been resolved, which previously caused some security software to flag the component as vulnerable.
In addition, KB5073724 includes Microsoft’s January 2026 Patch Tuesday fixes, which address 114 vulnerabilities, including one actively exploited and two publicly disclosed zero-day vulnerabilities.
Additionally, KB5073723 (OS Build 17763.8276) was released for Windows 10 version 1809. Both updates contain miscellaneous security fixes and general improvements to enhance overall system reliability and user experience.
However, if your PC isn’t compatible with the newer OS (Windows 11), you can enroll in the Windows 10 Extended Security Updates (ESU) program, which provides critical patches for one more year at no cost (until October 2026).
The update is now rolling out via Windows Update, and users can manually check for it by navigating to Settings > Windows Update.
2026-01 Cumulative Update for Windows 10 Version 22H2 for x86-based Systems (KB5073724)
Ensure your device is connected to a stable internet connection to download update files from the Microsoft server. Once done, you need to reboot your computer to apply the changes.
Alternatively, you can download the standalone installer directly from the Microsoft Update Catalog by searching for “KB5073724.”
Windows 10 KB5073724 Direct download links 64-bit and 32-bit (x86).
- Locate the patch next to the correct edition and version of the operating system.
- To install the update, simply run the downloaded MSU file and Windows will automatically install the cumulative update.
- If you are looking for the latest Windows 10 version 22H2 ISO, click here.
- In addition, you can download the latest Windows 11 ISO images here.
Uninstall Windows 10 KB5073724
If installing KB5073724 causes issues on your device, you can uninstall the update to revert the changes.
Uninstall KB5073724 using the Windows Update History tool
- Go to Windows Settings (Windows key + I) > Update & Security > Windows Update.
- From the right-hand pane, click on View Update History.
- Now, click on Uninstall updates.
- Select Update for Microsoft Windows (KB5073724) and press the Uninstall button.
Uninstall KB5073724 using the command line
Another quick way to uninstall this update is by using the command prompt. Here are the commands:
- Open the Command Prompt (Run > cmd)
- Run the following command:
wmic qfe list brief /format:table - This will show all the updates installed on the computer. Make sure KB5073724 is on the list.
- To uninstall the update, run the following command
wusa /uninstall /kb:5073724
The system needs to be restarted after uninstalling the update.
In addition, Microsoft has noted that Windows 10 version 21H2 reached end of service, meaning devices no longer receive monthly security and quality updates that protect against the latest security threats. Microsoft recommends installing the latest version 22H2 or Upgrade to Windows 11
How to Fix Common Issues with Windows 10 KB5073724
While the Windows 10 KB5073724 update brings significant improvements and fixes, some users may experience problems during or after installation. Here are proven solutions to resolve the most common issues.
Run the Windows Update Troubleshooter
The built-in troubleshooter can automatically detect and fix update-related issues.
- Press Windows + I to open Settings.
- Go to Update & Security > Troubleshoot.
- Click Additional troubleshooters.
- Select Windows Update and click Run the troubleshooter.
- Follow the on-screen instructions and apply any recommended fixes.
Check Your Internet Connection
A weak or unstable internet connection can cause the update to fail or get stuck.
- Use a wired Ethernet connection instead of Wi-Fi for better stability.
- Restart your router or modem.
- Temporarily disable VPNs or proxy servers.
- Test your connection speed using a service like Speedtest
Clear the Windows Update Cache
Corrupted update files in the cache can cause installation failures.
- Press Windows + R, type services.msc, and press Enter.
- Right-click the Windows Update service and select Stop.
- Navigate to C:\Windows\SoftwareDistribution\Download and delete all files inside the folder.
- Go back to Services, right-click Windows Update, and choose Start.
- Try installing the update again from Settings > Update & Security > Windows Update.
Repair Corrupt System Files
Damaged or missing system files can lead to update errors. Running SFC and DISM can help.
Open Command Prompt as administrator and run the following commands:
- sfc /scannow
- DISM /Online /Cleanup-Image /RestoreHealth
This will scan for corrupt system files and the Windows image for corruption and try to repair them. Let the scan complete 100%. Once it’s done, restart your PC and try installing the update again.
Check for Driver and Software Conflicts
Outdated or incompatible drivers can cause post-update issues like crashes or slow performance.
- Open Device Manager (Windows + X > Device Manager).
- Look for devices with a yellow warning icon and update their drivers.
- Update critical drivers (graphics, network, chipset) from the manufacturer’s website.
Windows 10 KB5073724– Frequently Asked Questions
Who qualifies for ESU and this update?
Eligible systems include Windows 10 devices on version 22H2 that enrol in the ESU programme. In certain regions, free enrolment options exist, in others, commercial options apply.
What if I don’t install KB5073724?
If you skip or fail to install the update and are enrolled in ESU, you may miss out on the first round of patched vulnerabilities. Even if you are not enrolled, your system now resides outside standard update support, exposing it to risk.
Is this update available via Windows Update only?
Yes, generally via the standard Windows Update channel for eligible systems. It may also be available via Microsoft Update Catalog for manual download.
When will the ESU support for Windows 10 end entirely?
Microsoft has not committed to an open-ended ESU timeline for Windows 10. It is a transitional programme.
Also read:
- Difference Between Windows 10 Feature Update and Cumulative Updates
- Windows Update won’t download or failed to install on Windows 10 (Solved)
- How to Share Files and Printers Between Two Windows 10 Computers
- Windows 10 keeps shutting down and restarting automatically. Try these solutions
- Complete Review of Microsoft Windows 10 Operating System
