Software & Apps Windows How to Fix D3dx10_42.dll Not Found or Missing Errors A Troubleshooting Guide for D3dx10_42.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 May 06, 2019 D3dx10_42.dll Error. Windows The Ultimate Laptop Buying Guide Tweet Share Email D3dx10_42.dll issues are caused in one way or another by an issue with Microsoft DirectX. Not to be confused with d3dx9_42.dll, which is also an issue having to do with Microsoft DirectX. The d3dx10_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, d3dx10_42.dll errors usually show up only when using these programs. There are many ways d3dx10_42.dll errors can show up on your PC. Here are several of the more common specific d3dx10_42.dll error messages you might see: D3dx10_42.DLL Not FoundThe file d3dx10_42.dll is missingFile d3dx10_42.dll not foundD3dx10_42.dll not found. Reinstalling might help fix this. D3dx10_42.dll errors appear when a game or other software program is started. The d3dx10_42.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 d3dx10_42.dll and other DirectX issues. This includes Windows 10, Windows 8, Windows 7, Windows Vista, Windows XP, and Windows 2000. How to Fix D3dx10_42.dll Errors Do not download the d3dx10_42.dll DLL file individually from any "DLL download site." There are several reasons that downloading DLLs from these sites are never a good idea. If you've already downloaded d3dx10_42.dll from one of those DLL download sites, remove it from wherever you put it and continue with these steps. If you've already downloaded d3dx9_43.dll from one of those DLL download sites, remove it from wherever you put it and continue with these steps. Restart your computer if you haven't yet.The d3dx10_42.dll error might be a fluke and 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 d3dx10_42.dll not found error.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 7, 8, 10, Vista, XP, and more. It will replace any missing DirectX 11, DirectX 10, or DirectX 9 file.Assuming the latest DirectX version from Microsoft doesn't fix the d3dx10_42.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.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 might have happened to the files in the program that work with d3dx10_42.dll and a reinstall could do the trick.Restore the d3dx10_42.dll file from the latest DirectX software package. If the above troubleshooting steps haven't worked to solve your d3dx10_42.dll error, try extracting the d3dx10_42.dll 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 drivers for the video card in your computer could correct this DirectX issue. Need More Help? If you're not interested in fixing this problem yourself, even with help, see my How Do I Get My Computer Fixed? piece 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.