Windows 10 SDK

The Windows 10 SDK (10.0.19041.0) for Windows 10, version 2004 provides the latest headers, libraries, metadata, and tools for building Windows 10 apps.

Use this SDK to build Universal Windows Platform (UWP) and Win32 applications for Windows 10, version 21H1 and previous Windows releases.

Getting started

You can get the Windows 10 SDK in two ways: install it from this page by selecting the download link or by selecting “Windows 10 SDK (10.0.19041.0)” in the optional components of the Visual Studio 2019 Installer.

Before you install this SDK:

  1. Review all system requirements
  2. Exit Visual Studio 2019 prior to installation.
  3. Review the Release notes and Known Issues.

Windows 10 SDK version 2104 and Server development

The Windows 10 SDK (10.0.20348.0), version 2104 is primarily intended for Windows Server development. For desktop development, see the release notes for changes you may benefit from by updating.

System requirements

The Windows SDK has the following minimum system requirements:

Supported operating systems

  • Universal Windows Platform (UWP) app development
    • Windows 10 version 1507 or higher: Home, Professional, Education, and Enterprise (LTSB and S are not supported)
    • Windows Server 2019, Windows Server 2016 and Windows Server 2012 R2 (Command line only)
  • Win32 app development
    • Windows 10 version 1507 or higher
    • Windows Server 2019, Windows Server 2016, and Windows Server 2012 R2 (Command line only)
    • Windows 8.1
    • Windows 7 SP1

(Not all tools are supported on earlier operating systems)

Hardware requirements

  • 1.6 GHz or faster processor
  • 1 GB of RAM
  • 4 GB of available hard disk space

Additional SDK requirements

Installation on Windows 8.1 and earlier operating systems requires KB2999226. To install through Windows Update, make sure you install the latest recommended updates and patches from Microsoft Update before you install the Windows SDK.

What's new

The Windows 10 SDK for Windows 10, version 2004 offers exciting new APIs and updated tools for developing your Windows applications. Learn more about the new features in Windows 10, version 2004.


To see the new APIs introduced with Windows 10, version 2004, see: What's new in Windows 10 for developers, build 19041.

Removal of api-ms-win-net-isolation-l1-1-0.lib

In this release api-ms-win-net-isolation-l1-1-0.lib has been removed from the Windows SDK. Apps that were linking against api-ms-win-net-isolation-l1-1-0.lib can switch t OneCoreUAP.lib as a replacement.

Removal of irprops.lib

In this release irprops.lib has been removed from the Windows SDK. Apps that were linking against irprops.lib can switch to bthprops.lib as a drop-in replacement.

Removal of wuapicommon.h and wuapicommon.idl

In this release we have moved ENUM tagServerSelection from wuapicommon.h to wupai.h and removed the header. If you would like to use the ENUM tagServerSelection, you will need to include wuapi.h or wuapi.idl.

Windows 10 WinRT API Pack

The Windows 10 WinRT API Pack lets you add the latest Windows Runtime APIs support to your .NET Framework 4.5+ and .NET Core 3.0+ libraries and apps. To access the Windows 10 WinRT API Pack, see the Microsoft.Windows.SDK.Contracts nuget package.

Universal C Runtime (UCRT)

The printf family of functions now conforms with the IEEE 754 rounding rules when printing exactly representable floating-point numbers and will honor the rounding mode requested via calls to fesetround. Legacy behavior is available when linking with legacy_stdio_float_rounding.obj.


Windows App Certification Kit

In this release of the Windows SDK, several new APIs were added to the Supported APIs list in the App Certification Kit and Windows Store. If there are APIs in the supported list that appear greyed out or disabled in Visual Studio, you can make a small change to your source file, to access them. For more details, see this known issue.

In addition to adding APIs, the following changes have been made to the tests:

Updated tests:

  • ValidateContentUriRules will be informational only. Test failures will be presented as warnings.

Removed tests

  • WebView WinRT access test for web app
  • PackageSizeCheck test for UWP apps
  • SupportedApi test for Desktop Bridge apps
  • AppContainerCheck test from BinScope for UWP apps
  • ServiceWorker check for all app types

New tests

  • High-DPI test. A new test for Desktop Bridge apps checks if the app uses DPI aware feature and warns if not specified. This test will encourage you to make your app per-monitor DPI aware. For details on DPI see High DPI Desktop Application Development on Windows.

Message Compiler (mc.exe)

Updates include:

  • Now detects the Unicode byte order mark (BOM) in .mc files. If the .mc file starts with a UTF-8 BOM, it will be read as a UTF-8 file. Otherwise, if it starts with a UTF-16LE BOM, it will be read as a UTF-16LE file. If the -u parameter was specified, it will be read as a UTF-16LE file. Otherwise, it will be read using the current code page (CP_ACP).
  • Now avoids one-definition-rule (ODR) problems in MC-generated C/C++ ETW helpers caused by conflicting configuration macros (e.g. when two .cpp files with conflicting definitions of MCGEN_EVENTWRITETRANSFER are linked into the same binary, the MC-generated ETW helpers will now respect the definition of MCGEN_EVENTWRITETRANSFER in each .cpp file instead of arbitrarily picking one or the other).

Windows Trace Preprocessor (tracewpp.exe)

Updates include:

  • Now supports Unicode input (.ini, .tpl, and source code) files. Input files starting with a UTF-8 or UTF-16 byte order mark (BOM) will be read as Unicode. Input files that do not start with a BOM will be read using the current code page (CP_ACP). For backwards-compatibility, if the -UnicodeIgnore command-line parameter is specified, files starting with a UTF-16 BOM will be treated as empty.
  • Now supports Unicode output (.tmh) files. By default, output files will be encoded using the current code page (CP_ACP). Use command-line parameters -cp:UTF-8 or -cp:UTF-16 to generate Unicode output files.
  • Behavior change: tracewpp now converts all input text to Unicode, performs processing in Unicode, and converts output text to the specified output encoding. Earlier versions of tracewpp avoided Unicode conversions and performed text processing assuming a single-byte character set. This may lead to behavior changes in cases where the input files do not conform to the current code page. In cases where this is a problem, consider converting the input files to UTF-8 (with BOM) and/or using the -cp:UTF-8 command-line parameter to avoid encoding ambiguity.


Updates include:

  • Now avoids one-definition-rule (ODR) problems caused by conflicting configuration macros (e.g. when two .cpp files with conflicting definitions of TLG_EVENT_WRITE_TRANSFER are linked into the same binary, the TraceLoggingProvider.h helpers will now respect the definition of TLG_EVENT_WRITE_TRANSFER in each .cpp file instead of arbitrarily picking one or the other).
  • In C++ code, the TraceLoggingWrite macro has been updated to enable better code sharing between similar events using variadic templates.

Signing your apps with Device Guard Signing

We are making it easier for you to sign your app. Device Guard signing is a Device Guard feature that is available in Microsoft Store for Business and Education. Signing allows enterprises to guarantee every app comes from a trusted source. Our goal is to make signing your MSIX package easier. See the documentation about Device Guard Signing.


Windows 10 app samples are now available through GitHub. You can browse the code on GitHub, clone a personal copy of the repository from Git, or download a zipped archive of all the samples. We welcome feedback, so feel free to open an issue within the repository if you have a problem or question. These samples are designed to run on desktop, mobile, and future devices that support the Universal Windows Platform (UWP).

Previous SDK versions

Previously released SDKs and emulators, including update details, can be found on the archive page.

API Light Up

When you use new APIs, consider writing your app to be adaptive so that it runs correctly on the widest array of Windows 10 devices. An adapative app "lights up" with new features wherever the devices and Windows version supports them, but otherwise offers only the functionality available on the detected platform version. For implementation details, see the Version adaptive code article.

Release notes and known issues

Windows 10 SDK, Version 2104 (released 5/26/2021)

  • SDK headers have been updated to address errors when compiling using the standard-conformant C preprocessor in the MSVC compiler cl.exe (/Zc:preprocessor, introduced in VS 2019 v16.6).
  • Fixed: “GdiplusTypes.h does not compile with NOMINMAX”. See Visual Studio Feedback.
  • When building with /std:c11 or /std:c17, you now get:
    • C99 tgmath.h
    • C11 static_assert in assert.h
    • C11 stdalign.h
    • C11 stdnoreturn.h

This release contains the following known issues, with suggested resolutions.

  • Clang/LLVM for Windows v11 targeting ARM64 is not compatible with the latest winnt.h
    • As a workaround, use the previous version of the Windows 10 SDK (build 19041), or clang/LLVM for Windows v10 when targeting ARM64 platforms
  • DirectXMath (including version 3.16 in this release) is not compatible with Clang/LLVM for Windows on ARM64.
  • The case of some header files were changed, to normalize them for case-sensitive file systems:
    • OAIdl.h, ObjIdl.h, ObjIdlbase.h, OCIdl.h, Ole2.h, OleAuto.h, and OleCtl.h were all made lower-case.
    • For Clang/LLVM for Windows builds, to support both older version and the latest Windows 10 SDK without warnings, add `-Wno-nonportable-system-include-path` to the CLI, or the following #pragma in source:

      #ifdef __clang__
      #pragma clang diagnostic ignored "-Wnonportable-system-include-path"

Windows 10 SDK, Version 2004 servicing update (released 12/16/2020)

This release contains the following files. If you encounter these issues, we recommend that you update your version of the SDK as soon as possible to avoid them:

  • Resolved unpredictable and hard to diagnose crashes when linking both umbrella libraries and native OS libraries (for example, onecoreuap.lib and kernel32.lib)
  • Resolved issue that prevented AppVerifier from working
  • Resolved issue that caused WACK to fail with “Task failed to enable HighVersionLie”

For known issues, see the winapi-sdk Q&A.

For new developer feature requests, submit through the Feedback Hub app under the category “Developer Platform/API.”

More resources

Downloads and tools

Get the latest editions of Visual Studio and Windows 10 development tools.


SDK archive

Find previous releases of the Window SDK and other tools.


Windows blog

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Windows lifecycle fact sheet

Find the key dates for Windows release updates and end of support.