Microsoft has released Windows 10 KB5073724 as part of its Extended Security Updates (ESU) program, continuing to provide critical protection for organizations and users who remain on Windows 10 after the operating system’s official end of support.
What is KB5073724 and why it matters
KB5073724 is the January 2026 cumulative security update for Windows 10 systems that are enrolled in the ESU program. Mainstream support for Windows 10 ended in October 2025, meaning regular consumers no longer receive free security patches. However, through ESU, Microsoft continues to deliver monthly security-only updates for businesses, governments, and other customers who need more time to transition to newer versions of Windows.
This update follows Microsoft’s traditional Patch Tuesday schedule and focuses strictly on security, reliability, and system integrity. There are no new features or visual changes — the goal is simply to keep supported Windows 10 installations safe in a rapidly evolving threat landscape.
What’s included in the update
KB5073724 addresses a range of security vulnerabilities across the Windows operating system, including issues related to the Windows kernel, authentication mechanisms, and networking components. Several of the patched flaws were rated critical, and some had the potential to be exploited for remote code execution or privilege escalation if left unpatched.
One important behind-the-scenes change in this update is the renewal of Secure Boot certificates. These certificates are essential for ensuring that only trusted software loads during system startup. Updating them helps protect systems against sophisticated boot-level malware that can bypass traditional antivirus tools.
The update also removes a set of legacy modem drivers that are no longer supported or considered secure. While most modern systems will not notice any change, environments that still rely on very old hardware should review this aspect carefully before deployment.
After installation, systems are updated to OS Builds 19045.6809 or 19044.6809, depending on the Windows 10 version in use.
Who will receive KB5073724
This update is not available to standard home users. It is delivered only to:
- Devices enrolled in the Windows 10 ESU program
- Certain Enterprise and Long-Term Servicing Channel (LTSC) editions
Eligible systems will receive KB5073724 automatically through Windows Update, Windows Server Update Services (WSUS), or enterprise management tools such as Microsoft Endpoint Configuration Manager.
What this means for Windows 10 users
KB5073724 reinforces Microsoft’s message that Windows 10 is now in a maintenance-only phase. While ESU customers continue to receive vital protection, the company strongly encourages planning a move to a newer Windows release. Cyber threats are becoming more advanced, and running an unsupported operating system without ESU coverage significantly increases security risk.
For organizations still dependent on Windows 10, this update provides reassurance that their systems remain protected — at least for now. However, ESU is a temporary bridge, not a long-term solution, and KB5073724 is another reminder that the clock is ticking toward full migration.
