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This security update resolves the following vulnerabilities in Windows:

  • MS17-004 Security Update for Local Security Authority Subsystem Service (3216771)

This security update also includes improvements and fixes from update 3207752. To learn more about the improvements and fixes in this update, see the December 13, 2016—KB3207752 (Monthly Rollup) entry in the Windows 7 SP1 and Windows Server 2008 R2 SP1 update history.

More Information


  • The security fixes that are listed in the "Summary" section of this Security Monthly Quality Rollup 3212646 are also included in January 2017 Security Only Quality Update 3212642. Installing either update installs the security fixes that are listed here. This Security Monthly Quality Rollup also includes improvements and fixes from previous monthly rollups.

  • If you use update management processes other than Windows Update and you automatically approve all Security updates classifications for deployment, both Security Only Quality Update 3212642 and Security Monthly Quality Rollup 3212646 are deployed. We recommend that you review your update deployment rules to make sure that the desired updates are deployed.

  • If you install a language pack after you install this update, you must reinstall this update. Therefore, we recommend that you install any language packs that you need before you install this update. For more information, see Add language packs to Windows.

How to obtain and install the update

Method 1: Windows Update

This update is available through Windows Update. When you turn on automatic updating, this update will be downloaded and installed automatically. For more information about how to turn on automatic updating, see Windows Update FAQ.

Method 2: Microsoft Update Catalog

To get the stand-alone package for this update, go to the Microsoft Update Catalog website.

More Information

Help for installing updates: Support for Microsoft Update

Security solutions for IT professionals: TechNet Security Troubleshooting and Support

Help for protecting your Windows-based computer from viruses and malware: Virus Solution and Security Center

Local support according to your country: International Support

File Information

For a list of the files that are provided in this update, download the file information for update 3212646.



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