How to download d3dx9_31.dll and fix Sims 3 error
If when trying to launch Sims 3 game you see an error: The program can’t start because d3dx9_31.dll is missing from your computer, below there’s a simple instruction on how to download the file, fix the error and get the game running.
D3dx9_31.dll file is a part of Microsoft’s DirectX gaming components and you shouldn’t download it separately (most often it doesn’t fix the error, but leads to another ones). Thought DirectX is already installed in Windows 10, Windows 8.1 and Windows 7, it doesn’t have all the DLL files some older games might need.
Download d3dx9_31.dll with DirectX package from the official website
The right way to download d3dx9_31.dll is to visit official page on Microsoft’s Website, download DirectX web-installer and launch it.
The official website is: https://www.microsoft.com/en-us/download/details.aspx?displayLang=en&id=35
Once finished installed, you can find d3dx9_31.dll file in your Windows/ SysWoW64 and System32 folders and “The program can’t start because d3dx9_31.dll is missing from your computer” will not occur again with Sims 3 or other games you’ve might experienced problems with.
Where to copy the file if I have downloaded it separately
If you’ve downloaded d3dx9_31.dll file from elsewhere, you may try to copy it to the folders I mentioned above or to Sims 3 root folder (along with the executable file), but probably there will be another error of the same type, so you better should use above mentioned method to fix the error.