Hi, I downloaded a student version of AC17 to upgrade from AC16. After downloading it I clicked and it brought the white hd on my desktop. I click that and the window with the round installer and then clicked the installer. A spinning white appears for a second in the middle of my desktop screen and then nothing after that. I looked in the Application folder but the only thing that is in it is Arc 16. Also, I tried to click the uninstaller for AC16 and it doesn't uninstall it. I have a iMac with OSX 10.7..5. Does anyone have any suggestions as to why the installer window won't open. picture enclosed. Thanks.