Programmed for Metro, what exactly does Metro do that it needs. I'm genuinely asking by the way not having a go.
Metro is a different desktop, with "different" ApIs. it does not run on "standard" ( not that thats the right word as both desktop and metro is standard win8, but you used it so) windows 8. It runs on metro part of win8, it would not run on win7.
Metro is a different deisgn ethos and although it shares most of the same kernal, it is not the same as win7.