I installed a recent (2012) game yesterday on windows 7 64-bit and when it finished it had a checkbox "Install DirectX". I clicked it and it showed progress installing but some of the files had the directx9_ description. That seemed bizarre because windows 7 already have the latest directx 11 version. Opening dxdiag it showed version directx 11. Is there any way i can re-install the latest version or that installer didn't change anything? Should i do a system restore prior to that installation or am i ok and have the latest version of directx? I want to have directx11 support in most of my games.
Many updates of the DX9c libraires were released continually after DX11 came out. If your game require DX9c, then your DX11 many not contains the most updated DX9c files. Just do the DX9c installation to get your DX9c updated. They can run happily together.