How to find your serial number?
PLA 3.0.5 or higher: The serial number is displayed in the PLA Login screen below the Login button.
PLA 3.0.0 - 3.0.4: In the PLA Login screen, click on "Tools", then select "License Management". In the License Management dialog, you will find your serial number in the "License information" section.
PLA 2.0: In the PLA Login screen, click on "License Information" then select "License Management". In the License Management dialog, you will find your serial number in the "License Details" section.