Disable WIN64DUALFOLDERS substitution in WiX

Question

I have a setup which chains 2 MSI files:

1. Either an x86/x64 MSI file that installs my product.
2. An x86 MSI file which deploys a third-party toolkit

I wanted the second MSI file to use the same install directory so MSI file 1 stores the user's selected directory in the registry which MSI file 2 then reads and uses as its target.

Fine and dandy - if I install MSI file 1 to C:\Test\ no problem - MSI file 2 picks this up and throws the tool kits into that folder.

When I install to C:\Program Files however... then MSI file 2 gets a bit to clever and decides I must have meant C:\Program Files (x86) and puts the tools in there - a bit messy.

It logs this when it does it:

  Action start 16:53:59: AppSearch.
  MSI (c) (2C:44) [16:53:59:521]: Note: 1: 2262 2: Signature 3: -2147287038
  MSI (c) (2C:44) [16:53:59:521]: WIN64DUALFOLDERS: 'C:\Program Files (x86)\' will substitute 17 characters in 'C:\Program Files\Manufacturer\Product' folder path. (mask argument = 0, the folder pair's iSwapAttrib member = 0).
  MSI (c) (2C:44) [16:53:59:521]: PROPERTY CHANGE: Adding INSTALLDIRECTORY property. Its value is 'C:\Program Files (x86)\Manufacturer\Product'.
  Action ended 16:53:59: AppSearch. Return value 1.

I am hoping to avoid bloating my setup too much with an x64 version of MSI file 2 (it is in the region of 20 MB), so my question is:

Is there a way I can avoid/disable this behaviour and get my x86 MSI file to trust me and write to "Program Files", not "Program Files (x86)"?

Answer 1

No, it can't be disabled. MSI enforces its rule that a 32-bit package cannot write to 64-bit portions of the file system (and registry).