To fix the issue with the missing d3dx9_30.dll file, you should install the DirectX End-User Runtime Web Installer. Here is how you can do it:
- Visit the official Microsoft DirectX download page.
- Download the DirectX End-User Runtime Web Installer.
- Run the installer and follow the prompts to install DirectX.
- After installation, restart your computer.
This should resolve the issue and allow you to run the game.