This was the article I was referencing. What particularly caught my attention
was the statement at the beginning of the article: "Single server
In this configuration, you have a single server that is configured to
function as a global catalog server, an Exchange computer, and an RPC proxy
server."

so what I take that to mean, is exactly what it says. The server needs to
have exchange on it, host a GC, and have the RPC over HTTP proxy component
loaded.

Later in the article it discusses that the registery needs to be modified on
all GC servers. The registry key it refeneces does not exist on my Exchange
box currently because it is not a GC. If I dont have to install AD that would
be great. However, this article leads me to believe that I have no other
choice.

If I were to not install AD on the exchange server, and modify the registery
on the domain controllers hosting GC's, would I then also need to load the
RPC over HTTP protocol on the domain controllers as well?

With this design it seems like we are moving to a multiple server
configuration instead of the single server configuration as referenced in the
title of the article. I don't see any way around making the exchange server a
DC. I would like to avoid this at all costs.