“The program can’t start because d3dx9.dll is missing from your computer. Try reinstalling the program to fix this problem” – this error often appears when you try to launch some old games that still require Microsoft DirectX 9. D3dx9.dll is a component of DirectX 9 and usually it is missing on Windows 7, 8, 8.1 and 10. Despite the fact that DirectX is already preinstalled on Windows 7, 8, 8.1 and 10, by default it is not fully installed, therefore you will need to manually install the missing library.
To get rid of d3dx9.dll is missing error you just need to download missing d3dx9.dll file from here: http://fix4dll.com/d3dx9_dll .
Now you can simply copy it into the root folder of the game or application that you are trying to run and it will work without d3dx9.dll is missing or not found error. Detailed installation instruction for Windows 7, 8, 8.1 and 10 64 and 32 bits you can find on the downloading page. Have a nice day.