I have Vegas Movie Studio HD Platinum 11.0. It's registered, the registration accepted my serial number. I installed from the the disc and when that didn't work, I downloaded the software from the service center and the same thing happened. Here is what happens: When I click to open software, I get a pop up that my trial has expired and I should either buy it or enter my S/N. I enter my S/N, click submit, and I get another pop up that says, "This application will restart to compete the upgrade process." So I click on OK and the pop up closes and it starts all over again.