Activate Windowblinds 6.1 Where Do I Click To Activate WindowBlinds 6?

Where do I click to activate WindowBlinds 6? - activate windowblinds 6.1

I downloaded the free trial version of WindowBlinds 6 http://www.stardock.com/products/windowblinds now have a serial number but do not know where to click to activate it, there should be a button or something that says Activate? Where can I find activate, click WindowBlinds 6?