It is often confused with the , but they serve different purposes: Change Frequency Product Code Identifies a specific release of a product. Changes with every major version. Upgrade Code Identifies a family of products across all versions. Stays the same throughout the product's life. Package Code Identifies a specific MSI file . Changes every time the installer is built. Administrative Usage
: In some licensing scenarios, the product code can be used to identify the software for which a license is required. installshield product code
: Changing version without changing Product Code (or using a proper minor upgrade table) breaks servicing. It is often confused with the , but