You are going to have to ask him for the Key Code to go along with the serial number. He should have that also if it has ever been activated. During the install, there is a point that asks for the Activation. I think you can skip it at that point, not sure. If you do want to activate it later, do the following. When you get the serial number and Key Code from him, look under the Help tab, there is a button called Product Activation. Click on it, fill in the information.