D3dx9_40.dll Errors

There are several ways that d3dx9_40.dll errors can reveal themselves on your computer. Here are several of the more common messages:

D3DX9_40.DLL Not FoundThe file d3dx9_40.dll is missingFile d3dx9_40.dll not foundThe program can’t start because d3dx9_40.dll is missing from your computer. Try reinstalling the program to fix this problem.D3dx9_40.dll not found. Reinstalling might help fix this.The code execution cannot proceed because d3dx9_40.dll was not found.

The error message could apply to any program that uses Microsoft DirectX, but it’s most commonly seen in video games, including Need for Speed, Gothic, Total War, and Psychonauts.

How to Fix D3dx9_40.dll Errors

Need More Help?

If you’re not interested in fixing this problem yourself, see How Do I Get My Computer Fixed? for a full list of your support options, plus help with everything along the way like figuring out repair costs, getting your files off, choosing a repair service, and a lot more. Usually, if a game or​ another program uses DirectX, the software developers will include a copy of DirectX on the installation disc. For example, if you’re using the game with Steam, it’s probably called DXSETUP.exe, and can be found in a redist folder in the game’s installation directory. If you can’t find it manually, try searching your entire computer for “dxsetup.exe” using a file search tool like Everything. Another example is the GB-ASManager program. When the DLL error is seen there, reinstall the software included on the associated DVD.