I'm using WiX to deploy my application. This application uses a registry key which is shared between x64 and x86 processes. Thus it must not use the Wow64Node. The application uses the KEY_WOW64_64KEY flag to achieve this.
But how can this be done using an MSI build with WiX? Currently I use an x86 and an x64 version of the installer, but that gives me a large overhead. Is it possible to disable registry redirection in WiX? I found the DisableRegistryReflection attribute, but that does not seem to have influence on redirection. Another idea would be to merge the two installers into a single file, like it is possible with languages. But I have in mind that that's not supported.
This could be done with an unified 32/64-bit package, but WiX doesn't support it. Some commercial setup authoring tools support it.
When using separate packages, 32-bit installers will use the 32-bit location on 64-bit systems. So to avoid registry redirection you should distribute a 32-bit package for 32-bit systems and a 64-bit package for 64-bit systems.
In 64-bit installers the registry entry component needs to be marked as 64-bit. In WiX you can do this by setting Win64 to "yes" for your registry components.