InstallShield 2015 » InstallScript Language Reference

If the IFX_PRODUCT_REGISTEREDSERIALNUM system variable’s value is not a null string (""), its value is used by the MaintenanceStart function to specify the data in the application uninstallation registry key’s ProductId value. This registry value provides information about the application to Add or Remove Programs in the Control Panel.

This system variable’s value is modified by end-user input in the Serial Number edit box of the SdCustomerInformation, and SdCustomerInformationEx dialogs.