D3dx9_43.dll file missing

We encountered this error when we installed LEGO MARVEL Super Heroes PC game on Love's Lenovo G470 CPU B970 2.3 GHz with Windows 7 Ultimate operating system. Fortunately, we were able to troubleshoot it and found a solution for the error.

D3dx9_43.dll issues are caused in one way or another by an issue with Microsoft DirectX. The d3dx9_43.dll file is one of many files contained in the DirectX software collection. Since DirectX is utilized by most Windows based games and advanced graphics programs, d3dx9_43.dll errors usually show up only when using these programs.

The d3dx9_43.dll error message could apply to any program that utilizes Microsoft DirectX, most commonly video games.
Any of Microsoft's operating systems since Windows 98 may be affected by d3dx9_43.dll and other DirectX issues. This includes Windows 8, Windows 7, Windows Vista, Windows XP, and Windows 2000.

1. Do not download the d3dx9_43.dll DLL file individually from any "DLL download site." 
2. If you've already downloaded d3dx9_43.dll from one of those DLL download sites, remove it from wherever you put it.
3. Restart your computer if you haven't yet.
   The d3dx9_43.dll error might be a fluke and a simple restart could clear it up completely.
4. Install the latest version of Microsoft DirectX. Chances are, upgrading to the latest version of DirectX will fix the d3dx9_43.dll not found error.
5. Microsoft often releases updates to DirectX without updating the version number or letter so be sure to install the latest release even if your version is technically the same.
6. The same DirectX installation program works with all versions of Windows including Windows 7, 8, Vista, XP, and more. It will replace any missing DirectX 11, DirectX 10, or DirectX 9 file.
7. Assuming the latest DirectX version from Microsoft doesn't fix the d3dx9_43.dll error you're receiving, look for a DirectX installation program on your game or application DVD or CD. Usually, if a game or other program utilizes DirectX, the software developers will include a copy of DirectX on the installation disc.
8. Uninstall the game or software program and then reinstall it again. Something might have happened to the files in the program that work with d3dx9_43.dll and a reinstall could do the trick.
9. Restore the d3dx9_43.dll file from the latest DirectX software package. If the above troubleshooting steps haven't worked to solve your d3dx9_43.dll error, try extracting the d3dx9_43.dll individually from the DirectX downloadable package.
10. Try reinstalling the DirectX update if the game you have installed encountered the same error or another error again.
11. Update the drivers for your video card. While it's not the most common solution, in some situations updating the drivers for the video card in your computer could correct this DirectX issue.
12. You may run System File Checker tool.
    How to use the System File Checker tool to troubleshoot missing or corrupted system files on Windows Vista or on Windows 7.

References:

D3dx9_43.dll file missing in Windows 7
How To Fix D3dx9_43.dll Not Found or Missing Errors 
DirectX End-User Runtime Web Installer 
Uninstall or change a program
Use the System File Checker tool to repair missing or corrupted system files