If you are creating 32-bit and 64-bit installs from the same InstallShield project, you will be changing the Template Summary property and using release flags to include the proper features when you build the releases. But what value do you put in INSTALLDIR when you want to install to the ProgramFilesFolder?
You have two choices, ProgramFilesFolder and ProgramFiles64Folder. However, you can just put ProgramFilesFolder into the INSTALLDIR property, and InstallShield will use ProgramFilesFolder when you are building a 32-bit install, and ProgramFiles64Folder when you are building a 64-bit install.
Note – July 2, 2012: I no longer use this method. To learn the current method that works reliably for me, go here: