Install - from scratch. So, I cant update to 9.1 as I need to have 9 installed for the update to work. I have tried the CD on 2 machines now, one Vista, on XP home, and same thing - invalid KEY. (I am using the printed key on the disc cover) Are the disks date dependant? Would changing the PC date help? There must be something the CD does first before the key entry as this disk worked fine last year.