I think I understand but just a "yes" or "no" will help. I've read lots on this but some is old info that is conflicting at best. I have read this, http://www.winsupersite.com/win7/clean_install_upgrade_media.asp but still have questions. I have XP Home installed. My PC was checked & Win7 will work fine. I KNOW I need to backup all my XP data because this will be a clean install that will erase all of my XP data. So, here's my questions; When the Win7 install disc is inserted does it detect the old version of XP or will I need to provide the XP key info or maybe both? Do both 32 & 64 versions come in Win7 Home upgrade? If so, can I install Win7 64bit even if I have XP Home which is 32bit? Thanks.