April 11, 2017—KB4015583 (OS Build 15063.138)

Improvements and fixes

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

• Addressed issues with updated time zone information.

• Security updates to Scripting Engine, libjpeg image-processing library, Hyper-V, Windows kernel-mode drivers, Adobe Type Manager Font Driver, Internet Explorer, Graphics Component, Active Directory Federation Services, .NET Framework, Lightweight Directory Access Protocol, Microsoft Edge and Windows OLE.

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

Known issues in this update

Microsoft is not currently aware of any issues with this update.

How to get this update

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

• Update replacement information
  This update replaces the previously released update KB4016251.

• File information
  For a list of the files that are provided in this update, download the file information for cumulative update 4015583. If you're installing a Windows 10 update for the first time, the package size for the X86 version is 51 MB and the package size for the x64 version is 114 MB.