Let me share my upgrade story: I decided to upgrade my kid's computer from Windows 7 to Window 10 and also replace the harddrive with an ssd drive. So I replaced the hard drive and installed the Windows 10 (home) from an ISO. But the windows 10 doesn't recognize the existing Windows 7 (home)product key. So this weekend I will have to put back the old harddrive with Windows 7, upgrade that to Windows 10, and then put the SSD back in and hopefully the Windows 10 on the SSD will recognize my product key.