The is a GUID (Globally Unique Identifier) used by the Windows Installer engine to identify a particular product or application version. While the human eye sees "MyApplication v1.0," the operating system sees 12345678-ABCD-1234-ABCD-1234567890AB .
For developers using CI/CD pipelines, InstallShield allows the Product Code to be updated via automation scripts or command-line parameters. This ensures that every "Major" build is distinct and trackable. The "Golden Rule" The most important rule for any setup developer is: Never reuse a Product Code for two different products.
Open the project file (.ISM or .ISPROJ). Navigate to General Information . The Product Code is displayed in clear text.
In legacy InstallScript projects (non-MSI), the Product Code serves a similar function but is managed differently via the Windows registry under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall . It still uniquely identifies the application, but you lose some MSI-specific upgrade features.