Software & Apps Windows How to Fix D3dx9_34.dll Not Found or Missing Errors A Troubleshooting Guide for D3dx9_34.dll Errors by Tim Fisher General Manager, VP, Lifewire.com Tim Fisher has 30+ years' professional technology support experience. He writes troubleshooting content and is the General Manager of Lifewire. our editorial process Facebook Twitter LinkedIn Tim Fisher Updated on October 27, 2019 Windows The Ultimate Laptop Buying Guide Tweet Share Email D3dx9_34.dll problems are caused in one way or another by a single root cause — a problem with Microsoft DirectX. The d3dx9_34 DLL file is one of many files contained in the DirectX software package. Since DirectX is used by most Windows-based games and graphics programs, d3dx9_34.dll errors usually show up only when you use these programs. Some of the more common d3dx9_34.dll error messages are listed below: D3DX9_34.DLL Not FoundFile d3dx9_34.dll not foundThe file d3dx9_34.dll is missingD3DX9_34.DLL is missing. Replace D3DX9_34.DLL and try againD3dx9_34.dll not found. Reinstalling might help fix thisThis application has failed to start because d3dx9_34.dll could not be found D3dx9_34.dll errors typically appear when a software program, usually a game, starts. Occasionally, d3dx9_34.dll errors display after a game is loaded but right before the game starts. In non-game applications, a d3dx9_34.dll error might appear before the program starts or before certain advanced graphics features of the program are used. The d3dx9_34.dll error message could apply to any program that relies on Microsoft DirectX, most commonly video games. Some common games that have been known to generate d3dx9_34.dll errors include "Call of Duty 4: Modern Warfare," "Crysis," "Need for Speed Pro Street," "Project 64" (an N64 emulator), "Blazing Angels: Squadrons of WWII," and "Savage 2: A Tortured Soul." Any of Microsoft's operating systems since Windows 98 may be affected by d3dx9_34.dll and other DirectX problems. How to Fix D3dx9_34.dll Errors Do not download the d3dx9_34.dll DLL file from any "DLL download" site. Downloading DLLs from these sites is never a good idea. If you've already downloaded a copy, delete it. Restart your computer if you haven't yet done so. The d3dx9_34.dll error might be a one-time problem and a restart could clear it up. It's unlikely this approach will fix the problem, but restarting is always a good first troubleshooting step. Install the latest version of Microsoft DirectX. Chances are, upgrading to the latest version of DirectX will fix the "d3dx9_34.dll not found" error. Microsoft often releases updates to DirectX without updating the version number or letter to install the latest release even if your version is technically the same. Assuming the latest DirectX version from Microsoft doesn't fix the d3dx9_34.dll error you're receiving, look for a DirectX installation program on your game or application CD or DVD. Most likely, if a game or another program uses DirectX, the software developers will include a copy of DirectX on the installation disc. Sometimes, though not often, the DirectX version included on the disc is a better fit for the program than the latest version available online. Uninstall the game or software program and then reinstall it again. Something may have happened to the files in the program that work with d3dx9_34.dll and a reinstall could do the trick. Restore the d3dx9_34.dll file from the latest DirectX package. If the above troubleshooting steps haven't worked to solve your d3dx9_34.dll error, try extracting the d3dx9_34.dll file individually from the DirectX package. 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 problem. Need More Help? If you don't want to fix 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 whole lot more.