Fix d3dx9_39.dll related errors in Half-Life: Alyx

One of the major frustrations of PC gamers is the infamous “[certain.dll] file is missing” type of errors. Often when install Half-Life: Alyx and try to play it, you will encounter this d3dx9_39.dll file missing error. In this post, we will learn how to diagnose d3dx9_39.dll related error in Half-Life: Alyx. Once we have diagnosed d3dx9_39.dll error in Half-Life: Alyx, we will look at various ways to fix it.

  • Developer: Valve Corporation
  • Publisher: Valve Corporation
  • Release Date: March 23, 2020

What You Need to Run Half-Life: Alyx

Minimum Half-Life: Alyx Requirements

  • Operating System: Windows 10
  • Processor: Core i5-7500 / Ryzen 5 1600
  • RAM/Memory: 12 GB RAM
  • Display Card: GTX 1060 / RX 580 – 6GB VRAM

Half-Life: Alyx Gameplay

How to Fix d3dx9_39.dll is missing error in Half-Life: Alyx

Download & install DirectX

DirectX is a bunch of APIs mixed together that handle multimedia related tasks such as playing high fi video games, video and 3D content. One of the basic steps to fix d3dx9_39.dll is missing error in Half-Life: Alyx is to just download and install the version of DirectX that is required by Half-Life: Alyx.

Typically, DirectX 9 or 11 do just fine for most video games.

Download DirectX 9

Download DirectX 11

Often, just downloading and installing DirectX will solve your problem. However, if you are still facing the problem. Let’s move on the next step, shall we?

Download & install d3dx9_39.dll

Another way of fixing d3dx9_39.dll is missing error in Half-Life: Alyx is to simply download d3dx9_39.dll file as per your PC configuration and install it in Windows\System32.

To download file from our secure servers, go to the following page: fix d3dx9_39.dll related errors