We had a question from the field that went something like this: "My customer is developing a stand-alone app that uses ADO. They wish to make this app available for download, so it needs to be as small as possible. They are concerned about the 6.5MB size of the MDAC 2.1 SP2 download (ADO 2.5 MDAC_TYP.EXE is now 7.7 MB). My (the consultant's) advice to them was to incorporate MDAC 2.1 SP2 into their install." The note went on to say that the customer wanted to create a program that would work with any version of ADO starting at 1.5. Interesting problem.
One of the MDAC crew came back with this "Unofficial MDAC Redistribution/Setup Rude FAQ."
Basically, think of MDAC setup as a service pack (SP) setup. Like an SP setup, it cannot easily be integrated with anything. Remember having to reboot three times when installing Visual Studio 6? This is the kind of install to expect when using MDAC.
Like an SP, MDAC must be hand-installed on each machine by a computer user who knows what he or she is doing (i.e., the average end-user does not know that you need to shut down various NT services in order to install MDAC, etc.).
So, my advice to customers is to write a setup that checks whether MDAC is installed or not, and if not, throws up a warning message and tells the user to install MDAC. This is sort of the same scenario as VS6 refusing to install unless you have NT 4 SP3 installed first. If you are doing a Web install, you can just point the user to the MDAC installer on the Microsoft Web site.