If you upgraded to Windows 10 on this PC by taking advantage of the free upgrade offer and successfully activated Windows 10 on this PC in the past, you won't have a Windows 10 product key, and you can skip the product key page by selecting the Skip button. Your PC will activate online automatically so long as the same edition of Windows 10 was successfully activated on this PC by using the free Windows 10 upgrade offer.
Which makes it sound like you don't, and can only upgrade or clean install on a single machine. I hope this is incorrect because I'm planning to upgrade my machine in 6 months.
From;
http://windows.microsoft.com/en-gb/windows-10/media-creation...
Which makes it sound like you don't, and can only upgrade or clean install on a single machine. I hope this is incorrect because I'm planning to upgrade my machine in 6 months.