Windows 10 SDK preview build 17046 now available for developers

Microsoft has rolled out a new preview build of the Windows 10 SDK to developers, bringing along a handful of changes for Windows 10 build 17046. This marks the fourth SDK preview release of the Redstone 4 testing cycle, and allows developers to target the latest Insider Fast Ring release.

Like previous releases, SDK preview 17046 includes the C++/WinRT headers and cppwinrt compiler, along with new MIDL key words. Here's a look at what's new, along with the known issues, and more.

What's New

  • C++/WinRT Now Available: The C++/WinRT headers and cppwinrt compiler (cppwinrt.exe) are now included in the Windows SDK. The compiler comes in handy if you need to consume a third-party WinRT component or if you need to author your own WinRT components with C++/WinRT. The easiest way to get working with it after installing the Windows Insider Preview SDK is to start the Visual Studio Developer Command Prompt and run the compiler in that environment. Authoring support is currently experimental and subject to change. Stay tuned as we will publish more detailed instructions on how to use the compiler in the coming week. The ModernCPP blog has a deeper dive into the CppWinRT compiler. Please give us feedback by creating an issue at:

Breaking Changes

  • New MIDL key words - As a part of the "modernizing IDL" effort, several new keywords are added to the midlrt tool. These new keywords will cause build breaks if they are encountered in IDL files. The new keywords are:
  • event
  • set
  • get
  • partial
  • unsealed
  • overridable
  • protected
  • importwinmd

Known Issues

  • "All tests run with Windows App Certification Kit will fail. During installation, please uncheck Windows App Certification Kit"
  • Installation on an operating system that is not a Windows 10 Insider Preview build is not supported and may fail.

A complete list of API updates and additions can also be found in Microsoft's full release notes. This SDK preview build is only supported by Visual Studio 2017, and can be installed alongside previously released SDKs. SDK preview 17046 can be downloaded from Microsoft now.

Dan Thorp-Lancaster

Dan Thorp-Lancaster is the former Editor-in-Chief of Windows Central. He began working with Windows Central, Android Central, and iMore as a news writer in 2014 and is obsessed with tech of all sorts. You can follow Dan on Twitter @DthorpL and Instagram @heyitsdtl