From Xojo Documentation
Used to indicate that the code has been compiled for or is running on Microsoft Windows.
result = TargetWindows
|result||Boolean||Returns True if you are compiling Windows code.|
TargetWindows indicates that your application compiled or running on Windows (using the Win32 platform, as opposed to something like .NET). This is True for both 64-bit and 32-bit apps. If you need to detect whether an app is 32-bit or 64-bit, use the appropriate constants: Target32Bit and Target64Bit.
Use this code to follow a different code path when running on Windows:
Using conditional compilation with the TargetWindows constant means that this code will only appear in Windows builds:
This example function can be used to detect if you application is building for a 64-bit version of Windows:
// Building for 64-bit Windows
// Building for 32-bit Windows
DebugBuild, XojoVersion, XojoVersionString, TargetBigEndian, TargetCocoa, TargetDesktop, TargetLinux, TargetLittleEndian, TargetMachO, TargetMacOS, TargetWeb, TargetX86, Target32Bit, Target64Bit constants; ＃If...＃Endif statement.