January 18, 2018—KB4075199 (OS Build 10240.17741)

Applies to: Windows 10

Improvements and fixes


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

  • Addresses issue where some customers on a small subset of older AMD processors get into an unbootable state.

  • Addresses issue originally called out in KB4056893 where calling CoInitializeSecurity with the authentication parameter set to RPC_C_AUTHN_LEVEL_NONE resulted in the error STATUS_BAD_IMPERSONATION_LEVEL.

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

After installing this update, some users may experience issues logging into some websites when using third-party account credentials in Microsoft Edge.

This issue is resolved in KB4074596.

How to get this 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 4075199.