I have 10 workstations that I am upgrading to Windows 10 Professional mainly from Windows 10 Home but I have 1 computer running Windows 7 Professional. I would like to do an "in-place" upgrade on this machine as well as to not lose any programs and applications. I have read numerous articles regarding how to do this. I understand I cannot do this for free. I have and OEM copy of Windows 10 Professional but that would require clean install which I am trying to avoid. Does anybody have a straightforward method to do this? I think I can download and run the Windows 10 Media installation Tool locally on the computer I am wanting to upgrade but I am getting conflicting information about where the licensing fits in. Do I purchase and provide License Key before installation? After installation? Any help in this matter would be greatly appreciated.