Just follow the steps below
How to Fix d3dx9_43.dll Missing Error for All Games and Apps in Windows
If you see the error message "d3dx9_43.dll is missing" on your PC, there is a problem. This error message usually appears after launching an application that requires DirectX to run. DirectX is essential for gaming on Windows, so if your game won't run and you see this error message, you'll need to troubleshoot the problem.
Fortunately, there are a few ways you can quickly repair Windows to restore DirectX functionality and fix the “d3dx9_43.dll is missing” error by following the steps below.
A "d3dx9_43.dll is missing" error could be a sign that you don’t have the version of DirectX installed on your PC that your game requires to run. While installing your game directly or through a game delivery service like Steam should result in all of the necessary packages being installed, this is not the case for DirectX on Windows 10.
