Windows Server 2003 SP1 Platform SDK Web Install

From Microsoft:

Microsoft Windows Server 2003 SP1 Platform SDK - April 2005 Edition. The Platform SDK for Microsoft Windows Server 2003 SP1 contains the information and tools you need to develop Windows-based applications. You can use this SDK to develop both 32- and 64-bit applications. This is no longer the most recent edition of the Platform SDK, please download the Windows Server 2003 R2 SDK - March 2006 Edition, (see related resources).

The Microsoft Windows Software Development Kit (SDK) provides the documentation, samples, header files, libraries, and tools you need to develop applications that run on Windows. The applications you develop with this edition of the SDK can run on the x86, x64 and Itanium-based versions of Windows Server 2003 SP1, Windows XP SP2, Windows XP x64 Pro Edition, and Windows 2000. A new custom install allows you to select components you wish to install on a more granular level. This version is the first release on CNET Download.com.