Software & Apps > Windows How to Fix D3dx9_42.dll Not Found or Missing Errors A troubleshooting guide for d3dx9_42.dll errors By Tim Fisher Tim Fisher Facebook Twitter Senior Vice President & Group General Manager, Tech & Sustainability Emporia State University Tim Fisher has more than 30 years' of professional technology experience. He's been writing about tech for more than two decades and serves as the SVP and General Manager of Lifewire. lifewire's editorial guidelines Updated on May 17, 2022 Tweet Share Email Tweet Share Email Windows The Ultimate Laptop Buying Guide D3dx9_42.dll issues are caused in one way or another by an issue with Microsoft DirectX. The d3dx9_42 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, these errors usually show up only when using these programs. Any of Microsoft's operating systems since Windows 98 may be affected by d3dx9_42.dll and other DirectX issues. This includes Windows 11, Windows 10, etc. D3dx9_42 Errors There are several ways d3dx9_42.dll errors can show up on your computer. Here are examples of the more common ones: D3dx9_42.dll not found. Reinstalling might help fix thisD3dx9_42.DLL Not FoundFile d3dx9_42.dll not foundThe program can't start because d3dx9_42.dll is missing from your computer. Try reinstalling the program to fix this problem.The file d3dx9_42.dll is missing These errors appear when a game or another software program is started, so it could apply to any program that utilizes Microsoft DirectX, like Autodesk's Maya or any other software program. However, d3dx9_42 DLL errors are most commonly seen when attempting to play video games. Some examples of video games that have been known to show the error when there's a problem with DirectX include Sid Meier's Civilization V, ArcheAge, State of Decay, Batman, The Lord of the Rings Online, Need for Speed Hot Pursuit 2011, The Legend of Pirates Online, F1 2010, Street Fighter, and Assassin's Creed: Brotherhood. How to Fix D3dx9_42.dll Errors Don't download d3dx9_42.dll individually from any "DLL download site". There are a number of reasons why downloading DLLs is never a good idea. If you've already done so, remove it from wherever you put it and continue with these steps. Restart your computer if you haven't yet done so. The d3dx9_42.dll error might be a fluke and, like many computer issues, a simple restart could clear it up completely. Install the latest version of Microsoft DirectX. Chances are, upgrading to the latest version of DirectX will fix the error d3dx9_42.dll not found. 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. The same DirectX installation program works with all versions of Windows including Windows 11, 10, 8, etc. It will replace any missing DirectX file. Assuming the latest DirectX version from Microsoft doesn't fix the error you're receiving, look for a DirectX installation program on your game or application DVD or CD (it might be called dxsetup or something similar). Usually, if a game or another program utilizes DirectX, the software developers will include a copy of it on the installation disc. Sometimes, though not often, the 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 might have happened to the files in the program that work with d3dx9_42.dll, and a reinstall could do the trick. Sometimes, the standard uninstall wizard for some programs and games don't remove every single trace of the program's files from the drive and registry, which might be causing additional issues or prevent the DLL from properly being used later. Try a free uninstaller program instead to be sure it all gets deleted. Restore the d3dx9_42.dll file from the latest DirectX software package. If the above troubleshooting steps haven't worked to fix the issue, try extracting the DLL file individually from the DirectX downloadable package. Update the drivers for your video card. While it's not the most common solution, in some situations, updating the video card drivers could correct this DirectX issue. 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 lot more. Was this page helpful? Thanks for letting us know! Get the Latest Tech News Delivered Every Day Subscribe Tell us why! Other Not enough details Hard to understand Submit