I never had anything on this PC before IP.
The PC was brand new (well the motherboard at least) and I installed Insider Preview to see how it would go. Was planning on buying Windows/installing Linux if I didn't like it. The only reason I can think of it activating itself is that the SSD I used had Windows 7 on it. But it was out of a laptop and the first thing I did was format it. The internet seems to be in consensus that IP users cannot upgrade to the full version unless they have a licence for Win 7/8.1. Microsoft says you cannot do this. But it happened. I even checked my product key and it was not the generic one I put in when I had IP.
I may not even buy Win 7. My GPUs are on their last legs, so I will probably need to spend money on them first.
I was just wondering if I can buy Windows 7 from the Microsoft Store and just buy the Upgrade version.
But I just read on the site:
Qualifying Operating System for purchase of Windows Upgrade License
Windows Vista (32-bit or 64-bit)
Business (N, K, KN) / NOTE: "N", "K", and "KN" are specialized editions available for certain markets
Business Blade PC Edition
Windows XP (32-bit or 64-bit)
XP Tablet PC Edition
XP Pro N
XP Pro Blade PC Edition
XP Home Edition
So it guess it won't work.