I've nearly finished building my new PC but i need to take my ssd from my current pc to the new one but I'm not sure how i would go about installing windows again as i originally have a windows 7 64bit disc and took the free upgrade to Windows 10. Is my windows 10 serial code the same as windows 7? Will i need to download a copy of win 10 or just use the win 7 disc and my free upgrade will still be there ?