I am interested in more details of how to chain MSI's.  I've been using merge modules to combine multiple products into one installer.  The Suite I install has products developed in three sites around the world.  It has been very difficult to get the install working correctly since we run into sequencing issues as all three products need to run custom actions throughout the install.

I would very much like to have each site develope their own MSI and then the suite installer could invoke each one and any install problems could be addressed by the team that built that installer.  In this talk it isn't clear to me whether Robert is talking about chaining as done in MSI 4.5, or whether he is talking about chaining via an executable (.exe) using MSI 3.1 (for example). 

My requirements are to support GPO installations.  This, as I understand it, precludes using a .exe chainer.  GPO requires an MSI package to be run without any command line configurations.  I need to supply an MSI.  I guess I could supply multiple MSI's but this makes life complicated for admins distributing the suite.

I'm evaluating MSI 4.5.  I understand it supports chaining via a new table in the MSI database.  I'm authoring the installer with Wix.  Does Wix support populating the chained install table?

Robert talked about "Advertising" applications as a key part of chaining.  Was this just a way to get around UAC prompts at each install?  My applications need to be installed at once, not on user access.  Our security software should run without the user doing anything.  Is there a way the parent installer could advertise each sub application and then invoke them to get them to install?