Impulse gives me the serial, but I still can't find where to TYPE the serial to activate WindowBlinds 6.
Click the Blue Stardock orb (top left) and select 'Register a product'. At the bottom of the next screen click on 'Add Registration'. From there fill-in the required info and that should do it.
If you require futher assistance, please ask and let us know if all goes well. After registering WindowBlinds you will be able to use Impulse to update WindowBlinds.