The PI-API for Windows is currently supported as a 32-bit (x86) and 64-bit (AMD64/EMT64 or x64) architectures. The PI-API for Windows has been available on every version of Windows. Older versions compiled for currently unsupported operating systems have been retired (Windows Alpha, Windows 16-bit). The 32-bit PI-API library may be used to create programs to run under both the Microsoft Windows 32-bit and 64-bit operating systems. The 32-bit library runs using the WOW64 layer on Windows 64-bit operating systems. The 64-bit library supports only Windows 64-bit (AMD64 or x64) operating systems beginning with Windows 2003.
Windows 32-bit Installation
Windows 64-bit Installation