I have two Macs, iMac and Macbook Air which I had PD 10 installed on the Macbook Air. My activation key is not working on the iMac. I am suppose to be able to use ONE activation key on TWO computers. I would like to activate PD 10 on the iMac. When I try to activate the key, I am getting an error message "Unable to confirm license key. You have reached the maximum number of activations". I know I had given my co worker ONE of my activations and that should leave me with another activation. How do I remove the activation on my Macbook Air? I believe PD 10 is still installed on my Macbook Air. How do I remove the activation key on the Macbook Air?