It used an *.xml file to store all the things which needed to happen to setup the system. File copies, registry entries, installing dependencies of various types, running scripts, configure windows features, IIS sites and directories and app pools and what-have-you, some other misc. stuff I forget now. Also would restart the computer if a restart return code was received, and would provision a user it would set up for auto-logon to resume install progress after the restart.

Each type of entry in the config file had a module which knew:

- How to check if the entry was already done and in a good state

- How to uninstall cleanly the thing (not actually needed; this was for system imaging)

- Usage of variables that would dynamically configure the system

- Variables also could conditionalize what gets installed

At the end of the day it was somewhere between a true installer engine and Powershell DSC (DSC would come about a few years later). This installer is probably no longer in use, as you can imagine more robust ways of solving this need exist now.

It was a heck of a lot of fun to build and watch it working though!