I\'m going round in circles trying to build an MSI installer for 64 bit output. I\'m using visual studio 2017 with the Installer Projects add-on from the store.
I j
The architecture is specified in the setup project's properties window which, confusingly enough, is not the same as the property pages, which is what you are showing there.
If you select the setup project in solution explorer and click F4 you sould see the properties window with AddRemoveProgramsIcon, Manufacturer and so on. Down that list is TargetPlatform where you specify x86 or x64.