Windows SDK Installation
Contents
Windows SDK Prerequisite Requirement
Before you can build C++ applications with RAD Studio or C++Builder, the Microsoft Windows SDK must be installed appropriately. The Windows SDK provides essential header files, libraries, and tools that the C++ compiler needs to build and link Windows applications. When you run the C++Builder compiler for the first time, RAD Studio automatically launches a configuration tool that patches the SDK header files to ensure compatibility with the IDE. This operation requires the SDK to be already installed; otherwise, the process will fail. Only the official Microsoft Windows SDK is supported — generic or third-party SDKs are not compatible and may lead to build errors or incomplete configuration.
RAD Studio version 13.0 has been tested with the July 2025 version of the Windows SDK, available as a web installer or an ISO download from the Windows SDK Archive page.
RAD Studio 13.0 has only been tested with the specified SDK version. For optimal performance and expected behavior, it is recommended to use that version.
SDK Installation
Suppose you choose to install C++ or Delphi support for RAD Studio before running the installer. In that case, RAD Studio checks the current Microsoft Windows SDK installation on the machine and, if none is found, provides a link to the latest version.
It is highly recommended that users install the Windows SDK before installing RAD Studio 13 Florence.
When installing the Windows SDK, it is recommended to enable the following options:
- Windows SDK for Desktop C++ x86 Apps
- Windows SDK for Desktop C++ amd64 Apps
It will also automatically activate the following:
- Windows SDK Signing Tools for Desktop Apps
- Windows SDK for UWP Managed Apps
- Windows SDK for UWP C++ Apps
RAD Studio supports several specific versions of the Microsoft Windows SDK:
- Windows SDK
10.0.26100.4654(July 2025) - Windows SDK
10.0.26100.4188(May 2025)
Currently, due to technical limitations, it is not possible to add a supported Windows SDK if an unsupported Windows SDK of the same major version (10.0.26100.x) is already present in the system. For a workaround, see the Roll back section below.
If you have an earlier version of the Windows SDK installed, the dialog shown below appears the first time you build a C++ project. RAD Studio attempts to copy SDK headers, but could not find at least one version of the Windows SDK that RAD Studio supports.
SDK at Build Time
When attempting to build a C++ project for the first time, the IDE will prompt you to create a Windows SDK by displaying the Add a New SDK window.
Fill out all the fields and click Ok to create a new Windows SDK.
While the new SDK is being created, the IDE is collecting headers from the MS SDK behind the scenes. Therefore, a prompt appears requesting users to allow copying the MS SDK headers to the $BDS/include/windows/sdk folder.
Selecting "Yes" begins the process of copying the headers.
It is important to note that several SDK headers, such as comdef.h, dmusici.h, or dmusicf.h, are deprecated. These are no longer part of the official Windows SDK. If your application needs these headers, grab a copy of an earlier version of C++Builder (v12 or earlier).
Roll back Windows SDK
This section explains how to refresh the Windows SDK version. To install a different SDK version, follow the steps below:
1. Uninstall all SDK versions by using the Control Panel and selecting the specific Microsoft Windows SDK version or the Windows Software Development Kit from the program list.
2. Install the desired version, as follows:
version 10.0.26100.4654
3. Next, delete all files in the $BDS/include/windows/sdk directory with the exception of the excpt.h file.
4. Finally, create a new C++Builder VCL application and build it to add the Windows SDK. In other words, rebuild the $BDS/include/windows/sdk.
As indicated in the sections above, supported SDK versions are available at the official Microsoft archive: https://developer.microsoft.com/en-us/windows/downloads/sdk-archive/