February 13, 2018—KB4074591 (OS Build 10586.1417)

Applies to: Windows 10 Version 1511

Improvements and fixes


This update includes quality improvements. No new operating system features are being introduced in this update. Key changes include:

  • Updates time zone information.

  • Addresses issue that causes services.exe to stop working after applying the "Obtain an impersonation token for another user in the same session” privilege to Windows Server 2012 R2 computers. These computers then enter a restart loop. The system may report the SceCli event ID 1202 with error 0x4b8. It may also report the Application Error event ID 1000 with the faulting module name scesrv.dll and the exception code 0xc0000409. This privilege was first introduced in Windows Server 2016.

  • Addresses issue where MMC application snap-ins—such as Services, Local Policy Admin, and Printer Management—fail to run when Windows Defender Application Control (Device Guard) is turned on. The error is "Object doesn't support this property or method."

  • Addresses issue with URL redirects in Internet Explorer.

  • Addresses issue where some users may have experienced issues logging into some websites when using third-party account credentials in Microsoft Edge.

  • Addresses issue with browser Compatibility View settings that occur during updates.

  • Addresses issue that decreases the Universal CRT’s performance in the _gcvt and _gcvt_s functions.
  • Addresses issue in which the output to a file or pipe was fully buffered in the Universal CRT for the standard error (STDERR) stream.
  • Addresses issue in the Universal CRT by adding the "x" access mode flag to support the fopen() function.
  • Addresses issue with a race condition in the Universal C Runtime (CRT) that occurs when you update the global locale. The issue corrupts the current locale reference count and triggers a double free condition.
  • Security updates to Microsoft Edge, Internet Explorer, Microsoft Windows Search component, Windows Kernel, Device Guard, Windows storage and file systems, Common Log File System driver, and the Microsoft Scripting Engine.

If you installed earlier updates, only the new fixes contained in this package will be downloaded and installed on your device.

For more information about the resolved security vulnerabilities, see the Security Update Guide.

Known issues in this update


Symptom Workaround
Because of an issue that affects some versions of antivirus software, this fix applies only to computers on which the antivirus ISV updated the ALLOW REGKEY.

This issue is resolved in KB4088779.

How to get this update


This update will be downloaded and installed automatically from Windows Update. To get the standalone package for this update, go to the Microsoft Update Catalog website.

File information

For a list of the files that are provided in this update, download the file information for cumulative update 4074591.