I have the GMAT Premier Program 2009 edition and am having problems. First, the CD doesn't work with Vista. I can live with that, but I can't get the online companion to work. I did figure out that you don't enter the serial number, but even going around the other way (clicking the link for the 2009 edition below the image of the book) I still am not getting anywhere. It's telling me that the code has already been used, even though I've not entered any code or numbers. So, I have a registered account, but can't access the diagnostic test, etc. Any suggestions?