Enter the path to the DLL you use to validate serial numbers. Alternatively, you can click the browse button and navigate to this file. Before you can set this property, you must set the Show Serial Number property to Yes. When a customer enters a serial number in this dialog, it will be passed to your DLL for verification. If the serial number is successfully verified, the installation can continue. If the serial number is invalid, the installation will end, depending on how many retries you allow in the Retry Limit field. See Serial Number Validation for more information.