Problem

We would like to use GenerativeComponents with AECOsim Building Designer for building design, as well as GenerativeComponents with MicroStation for bridge design. However, we routinely need to install on over a hundred machines so need to implement a silent installer.  How can I force a silent install to install GenerativeComponents on one application only?  When using the msiexec /qb switch, that I believe should allow a choice between AECOsim Building Designer or MicroStation, only the AECOsim installation is installed correctly. None of the switches I've tried seem to help: BSI_INSTALLONMS, BSI_INSTALLONABD, USERSELECTEDMSINSTALLDIR, and BSI_POWERPRODUCTPROGRAMDIR.

Solution

Unfortunately there is no means to allow a silent install to default to MicroStation if both it and AECOsim Building Designer already exist on the same machine.  The installer itself includes a number of VB script sub-routines and one of these does a check for the existence of MicroStation and AECOsim Building Designer (in that order).  The end result is that AECOsim Building Designer is last in, so it is used as the base application for the install since the dialog to choose a base application is bypassed.  This particular script is shared amongst all Bentley installers so moving MicroStation from the first position is not possible without affecting every other product installer.

The install workflow recommended in this case is: 

1. First uninstall any existing installations of AECOsim Building Designer and GenerativeComponents. 
2. With only MicroStation installed, run the silent installer for the GenerativeComponents Extension which will default to MicroStation since that is the only base application available.
3. Install AECOsim Building Designer.
4. Run the installer for the GenerativeComponents Extension again, which should now default to AECOsim Building Designer for the reasons outlined above.

Note: When using the switch BSI_INSTALLONABD=1 you will also need to use BSI_INSTALLABDADDIN=1 so that the AECOsim Building Designer/GenerativeComponents SELECTseries integration works properly.   For example:
 msiexec /log c:\GC_sILENTiNSTALL.log /qn INSTALLDIR="C:\PROGRA~2\Bentley\ABDUPD~1\AECOsimBuildingDesigne" BSI_CREATE_DESKTOP_SHORTCUT=1 BSI_INSTALLABDADDIN=1 BSI_INSTALLONABD=1 /i "GenerativeComponentsExtension.msi"