by Microsoft

D3dx9_42.dll is an error where you need to reinstall

Operating system: Windows

Publisher: Microsoft

Antivirus check: passed

Last revision: Last week

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You probably came to this page because of an error related to the absence of a D3dx9_42.dll file in your system. This file is a DLL, which contains standard library functions used to develop games and programs. First, let's take a look at how to solve the problem and then talk a little bit about the contents of this DLL.

A versatile solution

The first and most obvious solution to this problem is to install DirectX, as this file is part of this package. You can download the DirectX distribution from our website. If this package has already been installed on your computer - just update it, you don't need to uninstall the previous version. By installing DirectX you can solve not only this problem, but also potential problems in the future, because the game (or program) may need not only D3dx9_42.dll, but also other files from this distribution.

An alternative, additional solution

Here we will cover manual copying of the file to the required folders. If you've thought about this option from the beginning, you'd better start by taking the first advice. If you still need to add this file to the system manually, download it from this page and use the instructions inside the archive. Copy the file to all proposed folders and register it in the system.

For the record:

D3dx9_42.dll contains 329 functions that serve such tasks as drawing lines, forming geometry of objects, mathematical calculation of various graphical parameters, texture processing, etc. From this, it becomes clear why so many games need this DLL-library.

I believe this is an add on for rendering or graphics program.I can't tell you if most of these programs have these things in there library but if it doesn't it would be useful.
The d3dx9_42 dll file is one of Microsoft's system files. It is important because any malfunctioning in this file can cause issues when you try to launch a program or game on your system. For example, you might face an error message if the file is broken or missing. Downloading the file can help keep things on your device running smoothly.
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