I need to ensure client machine has Microsoft.mshtml installed in the GAC.
And if not, deploy it.  My app is a Browser Helper Object and depends on
mshtml.

Initially, I thought I could take care of deploying mshtml within my install
.msi (VS.NET
setup/deploy project).  But if I simply add mshtml to the GAC from my
install, the install
fails near the end with the error:

    "Unable to get installer types in the <mydll>.dll assembly.  One or
more of the types
      in the assembly unable to load."
   ((Yes, I'm using fusioninstall.cs in my project but it
        is unrelated to mshtml and works perfectly as long as mshtml is
excluded))

It is just mshtml.  Add it to the GAC, get the error.  Change mshtml to go
in app folder.  No error.
Even started over on a new, minimal test project.  Got the same error there.

To workaround, I have two separate installs.  First one deploys Mshtml.
Second one installs
my app.  But, I know there's a way to get this into a single installl.  How?

So, is this behavior by design and you aren't supposed to deploy
Microsoft.mshtml this way?
Is there a preferred way to deploy Microsoft's PIAs?

Thanks for your help!