I had purchased Windows 7 upgrade about 2 years ago, downloaded and saved it as an ISO CD. I just had to format my hard drive and re-install. The installation completed but never asked for my Key Code. I checked Control Panel > System and found a temporary key code valid only for 15 days. When I changed the key code, I was advised of a "failure" because this Windows 7 was an "upgrade." Yes, I had upgraded from XP. Must I re-install XP and then install W-7 as an upgrade? Is there any way around this issue?