I have Windows 7 Professional Upgrade disk. My system is/was XP Professional. I began the upgrade and had some difficulty in booting from the Win 7 upgrade disk and had to re-start several times. Eventually the installation began, formatteed the had drive and installed. At the Activation page I entered the Product Key and got an error message ".. this Product Key is for an Upgrade version only ....", or something like that. Did the re-format of the hard drive and deletion of the existing XP sysytem void the Upgrade? J M Harper