Source Video: http://channel9.msdn.com/Events/Build/2014/9-004 "Windows Graphics and DirectX 12" panel at BUILD
Sorry Netbook users but it looks like the only version that isn't supported is Starter.
In summary, they had a spokesperson from Microsoft answer questions about DX12 and the first one that was asked was how far back DirectX 12 would be supported. He answered that they wanted to support the largest install base possible, so Windows 7 was the most logical step, due to all the people migrating from XP to 7.
This is fantastic news and one of the many great steps Microsoft has been making to become a better company due to the death of the 'Strategy Tax'. Satya Nadella has been making been making some amazing progress as Master Chief Executive Officer (Get it? ) and IMO, the future of Microsoft is going in a much better direction.
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