DCOM samples in the Win32 SDK.

OLEIMP   -- The OLEIMP sample demonstrates a method for emulating auto 
            impersonation of clients.

SIMPLE   -- The SIMPLE sample demonstrates the minimum requirements to use 
            a COM object, whether it is on the same machine or on a different 
            machine.  This sample consists of a client and a server portion.

SECURE   -- The SECURE sample consists of a client portion and a server 
            portion.  Its purpose is to demonstrate client-side and server-
            side security in a Distributed COM application.

COMPERF  -- The COMPERF sample demonstrates the performance of DCOM in 
            several different programming scenarios.

DCOMPERM -- The DCOMPERM sample provides source code and several wrapper 
            functions to simplify the process of manipulating the access 
            and launch permissions for a COM server. Additionally, this 
            sample provides code which demonstrates how to set and retrieve 
            the RunAs password for a COM server.
            (sample located in \mstools\samples\win32\winnt\security\dcomperm)