That is simply wrong. DirectX11 is able to run directly on DirectX10 and 10.1 hardware. I explained how it is able to do that quite clearly in my previous post even including developer documentation directly from Microsoft for further reading. Plugging your ears and repeating your incorrect assumptions isn't going to change the facts here. How about a list of DX11 games that don't run on DX10.1 hardware? It would be a pretty short list, if it had any games on it at all, because that would be the exception rather than the rule. I've run my 4870x2 cards for many years now and I can't think of even one single DirectX11 game that has ever given me issues when played on my DirectX10.1 hardware. In no way does Running a DirectX11 game on 10 or 10.1 hardware mean you have to revert back to using DirectX9. The reason games still include a DirectX9 executable has nothing to do with DX10/10.1 hardware, but rather, so that the game is able to run on WindowsXP.