Im downloading windows 10 64 bit now. However, on the download page it says
"If you will be installing the operating system for the first time, you will need your Windows product key (xxxxx-xxxxx-xxxxx-xxxxx-xxxxx). For more information about product keys and when they are required, visit the FAQ page.""
Is that MY WINDOWS 7 KEY?
Must be. But, i would download the ISO and then go back and do an upgrade. Remember, you have to do an upgrade first before you can do a clean install. Once the upgrade has activated then you can do a clean install.