d3dx9.dll is missing or not found or installed
So this error message has been doing the rounds lately. This application has failed to start because d3dx9_32.dll was not found. Or other error messages around d3dx9.dll, dxdx9d.dll, d3dx10.dll, xinput.dll, xact.dll, d3dx10_33.dll, d3dx9_40.dll and other variations being missing, not being found or installed. These are all optional components to DirectX that may not be installed with the version of DirectX you already have on your system. Typically these will be installed when the game installs DirectX, however for historical reasons a lot of gamers, knowing they had the latest version of DirectX didn't bother (I never do either)....