InstallAware for Windows Installer

Set 64 Bit Mode

This command determines the processor architecture used by the installation. This command may be used to set processor architectures while setup is already running on the target system, making it possible to ship a single installer for both 32 bit and 64 bit Windows, switching by processor architecture at runtime.

The Get System Settings command may be used with the Windows in 64 bit Mode flag (detecting AMD64/EM64T/IA64 processors only) and Windows on ARM (detecting the ARM64 processor only) flags to determine the availability of 64 bit capabilities at runtime.

The Get System Settings command may also be used with the Processor Architecture flag to determine the exact 64 bit architecture of the underlying processor (IA64 or AMD64/EM64T or ARM64).

Win32

Setting this option when setup is running on 32 bit Windows performs a native 32 bit installation. On 64 bit Windows, setup performs a compatibility mode 32 bit installation.

Itanium ia64

Setting this option when setup is running on 64 bit Windows with an Intel Itanium processor performs a native 64 bit installation. On any other operating system and processor combination, setup fails when Apply Changes is called with the Windows Installer engine.

x64

Setting this option when setup is running on 64 bit Windows running on an AMD64/EM64T/ARM64 processor performs a native 64 bit installation. On any other operating system and processor combination, setup fails when Apply Changes is called with the Windows Installer engine.

Warnings

When applications are running on 64 bit Windows in 32 bit compatibility mode, Windows redirects file system and registry access to alternate 32 bit compatibility locations. This may cause undesired behavior with your setup if you call the Set 64 Bit Mode command after other commands that access the file system and registry. The commands that have already accessed the file system and registry will have returned incorrect 32 bit compatibility values that will not accurately reflect the true state of the 64 bit system.
Always call the Set 64 Bit Mode command before any commands that may access the file system and registry to assure correct 64 bit returns from those commands. If you have to call the Set 64 Bit Mode command after having accessed the file system and registry, call the file system and registry commands again to obtain correct 64 bit returns.
Choosing a 64 bit installation mode while running on 32 bit Windows, or choosing an incorrect 64 bit processor architecture while running on 64 bit Windows, does not cause setup to immediately fail. Setup will continue to run normally until an installation, maintenance, patch, advertisement, or uninstall operation occurs with the Windows Installer engine.
64 bit runtime installations are available. Some runtimes are designed to install on both 32 and 64 bit platforms, while others are designed to install on only 32 bit, or only 64 bit platforms. You may use custom scripting to always install the correct set of runtimes based on the target platform.
Commands and plug-ins that load executable code into memory will not work with 64 bit executables, even when setup is running under 64 bit installation mode. Such commands and plug-ins include Register Library and Call DLL Function. You may use the various alternatives to such commands when running in 64 bit installation mode.

Notes

When restarted, setup remembers the processor architecture previously set by this command (unless setup ends with an uninstallation).
The default processor architecture in every InstallAware setup is Win32. To build a setup that always runs in 64 bit mode, simply insert a Set 64 Bit Mode command on the first line of your setup with the Itanium ia64 or x64 option selected.
It is legal to call this command multiple times with different processor architecture options. You may do so to obtain both 32 bit and 64 bit returns from commands that access the file system and registry on the target system.
It is NOT legal to call Apply Changes in the same setup after changes have already been applied under a different processor architecture. Every time Apply Changes is called, the same processor architecture must be set, even though the processor architecture may have been changed in between the calls.
To install files into 32 bit folder locations when running in 64 bit mode, obtain the folder locations in 32 bit mode, then install the actual files in 64 bit mode.
To write to 32 bit X86 registry locations when running in 64 bit mode, specify the full 32 bit X86 registry paths when writing to the registry while setup is in 64 bit mode (including the Wow6432Node string in the key path).
To write to 32 bit ARM32 registry locations when running in 64 bit mode, specify the full 32 bit ARM32 registry paths when writing to the registry while setup is in 64 bit mode (including the WowAA32Node string in the key path).