Because Windows 7 is the oldest OS still supported by Windows for a considerable amount of time.
At this point I've just said to hell with windows. I threw 2008 R2, but apparently the key I had was overused, so I tried to install server 2016. The CPUs don't support specific features needed by 2016.
Tried Server 2012 R2. It crashes whenever I launch the installer from boot, and when I run the setup from windows (I've extracted the ISOs to a separate partition) it installs, then gives up half way.
So screw Windows, most of what I can do can run on Linux and it can be still installed from DVD for old bastards like me who still use the format.
And yes, it does fit on a dual layer DVD, but my wallet doesn't. They are
Excuse me, I just checked the prices, they aren't that insane anymore.
But I am still running Linux, which is weird because the server ran Server 2012 fine, but I think it was 2012 R1, which I can't get anymore.