This document provides an overview of InstallShield and discusses topics like 32-bit vs 64-bit installations, packaging options for upgrades and patches, replacing existing files and registry entries, and removing installed data. It covers key differences in folder structures, registry locations, and component settings between 32-bit and 64-bit installations. Major upgrades allow changing most aspects of the installation whereas small and minor upgrades have more limitations. Precise rules are outlined for replacing existing files based on version, date, and language. References are provided for further reading on Windows installation topics.