description: "How to set the target SDK version in a Windows Desktop application project to use the Windows 10 SDK."

ms.date: "01/22/2020"

When you create a new classic Windows desktop project in Visual Studio, it targets the Windows 10 SDK by default. Visual Studio installs a version of the Windows 10 SDK when you install the C++ Desktop workload. This version of the Windows SDK is compatible with Windows 7 SP1 and later. For more information about targeting specific versions of Windows, see [Using the Windows Headers](/windows/win32/WinProg/using-the-windows-headers).

When you upgrade an existing project, you have a choice: You can keep using the target Windows SDK specified in your project. Or, you can retarget your project to use the Windows 10 SDK. With the Windows 10 SDK, you get the advantages of support for the latest operating systems and language standards.

Starting with Visual Studio 2015, the C Runtime (CRT) library was separated into two parts: One part, ucrtbase, contains the Standard C and Microsoft-specific CRT functions that you can use in Universal Windows Apps. This library is now known as the Universal CRT, or UCRT, and has moved into the Windows 10 SDK. The UCRT contains many new functions, such as C99 functions, needed to support the latest C++ language standards. The other part of the original CRT is vcruntime. It contains the C runtime support, startup, and termination code, and everything else that didn't go into the UCRT. The vcruntime library gets installed along with the C++ compiler and toolset in Visual Studio. For more information, see [CRT library features](../c-runtime-library/crt-library-features.md).

The UCRT is now a system component that's installed on every version of Windows 10. It's also available as an installable component for all earlier supported versions of Windows. You can use the Windows 10 SDK to target all the supported versions of Windows. For a complete list of supported operating systems, see [Windows 10 SDK](https://developer.microsoft.com/windows/downloads/windows-10-sdk).

To update your projects to use the UCRT when you upgrade from a project version before Visual Studio 2015, follow these steps:

1. Make sure the Windows 10 SDK is installed. The Windows 10 SDK is installed as part of the **Desktop development with C++** workload. A standalone version is available at [Downloads and tools for Windows 10](https://developer.microsoft.com/windows/downloads).

1. Open the shortcut menu for the project node, and choose **Retarget projects**. (In earlier versions of Visual Studio, choose **Retarget SDK Version**.) The **Review Solution Actions** dialog appears.

1. In the **Target Platform Version** dropdown list, choose the version of the Windows 10 SDK you want to target. Generally speaking, we recommend you choose the latest installed version. Choose the **OK** button to apply the change.

The 8.1 in this context refers to the Windows 8.1 SDK.

1. Open the project properties, and in the **Configuration Properties, General** section, notice the values of **Windows Target Platform Version**. Changing the value here has the same effect as following this procedure. See [General Property Page (Project)](../build/reference/general-property-page-project.md).

This action changes the values of project macros that include paths to header files and library files. To see what changed, open the **Visual C++ Directories** section of the **Project Properties** dialog. Select one of the properties, such as **Include Directories**. Then, open the property value's dropdown list, and choose **\<Edit>**. The **Include Directories** dialog appears.

1. Repeat for other solution projects, as needed, and rebuild the solution.

You can also *target*, or use, an earlier version of the SDK in a project. Open **Project** > **Properties**. Choose from the other SDK versions available on your computer in the **Windows SDK Version** dropdown.

1. Open the shortcut menu for the project node in Solution Explorer, and choose **Retarget projects**. (In earlier versions of Visual Studio, choose **Retarget SDK Version**.)

[Walkthrough: Create a traditional Windows Desktop application (C++)](../windows/walkthrough-creating-windows-desktop-applications-cpp.md)