How to fix Error d3dx9_43.dll missing on the computer

The error about the absence of the d3dx9_43.dll file in the Windows operating system most often occurs when you try to start a game or other application that uses the DirectX graphics subsystem. We will understand the causes of the problem, as well as the ways that will allow you to fix it.


  • 1The computer is missing d3dx9_43.dll: what does the error mean
    • 1Causes of the problem
  • 2How to fix the error
    • 1Checking for viruses
    • 2Registering the library via the command line
    • 3Deleting and restoring a library
    • 4Cleaning the operating system registry
    • 5Updating Drivers
    • 6Download and Install DirectX
    • 7Video: d3dx9_43.dll error elimination
  • 3What to do so that the error does not occur again

D3dx9_43.dll is missing from the computer: what does the error mean?

The error of the form “d3dx9_43.dll is missing on the computer, the program cannot be launched” is due to the absence of the DirectX version 9 library installed (this version of the API was released together with Windows XP and is mainly used in old games and applications).

This library is an implementation of an API from Microsoft for low-level operation of programs with computer hardware resources. Simply put, using it, a program or game will be able to “correctly” access the sound card, video accelerator, and input / output devices (including a gamepad).

Can this error occur in Windows 7, 8, 10? Yes, even if DirectX higher than 9th version is already installed on the computer. All API versions will need to be installed to support legacy apps and games.

Causes of the problem

Most often, the error indicates that the operating system was recently installed and DirectX has not been installed yet.

The lack of a library bundled with Windows is due to the fact that some patents from manufacturers of graphics processors, sound cards and HID devices may be violated. That is, this is a purely legal formality.

Also, a problem related to the d3dx9_43.dll library may occur in the following cases:

  • damage to the hard disk (the appearance of “bad” sectors when the information recorded on them is erased);
  • the DirectX library was replaced (it happens when trying to install an outdated version of the API, for example, DirectX 8);
  • damage to the OS by viruses (they often replace system libraries with third-party dll files, into which malicious code is embedded);
  • problems with the registry – the DirectX library is not registered in it for some reason (although the d3dx9_43.dll file itself is in the system);
  • outdated drivers are installed on the sound card, graphics accelerator, HID devices (DirectX support for devices is implemented just through the drivers).

How to fix the error

It is not always possible to establish the exact cause of the error, so you will have to try all possible methods to eliminate it. The first step is to check the system partition for viruses, then try to register the library using the command line. It is also worth trying to clean the registry, update drivers (in particular, sound and graphics cards). And if DirectX was not previously installed, it should be downloaded from the official Microsoft website and installed.

Virus check

Even if the d3dx9_43.dll file is present on the system disk (it is located in the C: \ Windows \ System32 directory), it is quite possible that it was replaced by a damaged or virus-infected file. And by the way, such virus programs quite often replace several libraries at once, disrupting the operation of the operating system. Therefore, you should start by checking your computer for viruses.

By default, Windows 7 has a built-in antivirus program Microsoft Security Essential (Home Advanced and higher editions). If it is not in the list of installed applications (in Windows 8, 8.1, 10 it is referred to as Windows Defender and is already integrated into the system), then you will first need to download it from the official website ( / security-essentials) and install. The utility is provided free of charge.

After installation you will need:

  1. Start Microsoft Security Essentials by clicking on the shortcut on the desktop.
  2. In the window that appears, go to the “Update” tab and select “Update”.Update the program to the latest version, if required
  3. Wait until the updates are installed (you may need to restart your PC – follow the instructions that will appear on the display), go to the “Home” tab and click “Check now”.
  4. Wait until the end of the check (takes 5 to 20 minutes, on average).The check usually takes about 20 minutes

If the user does not want to install an antivirus from Microsoft for some reason, then you can use the free Dr.Web CureIT! Utility. You can download it from the official website (

Next, you need to launch the application and select “Start check”, wait for it to end.

You can check your computer using the free Dr.Web CureIT!

The key feature of the CureIT utility is that there is no need to install it. At the same time, the program allows you to check not only the system partition, but also all installed hard drives.

Registering the library via the command line

This action will help in the event that the DirectX library for some reason was not registered in the registry (software error or OS failure).

Algorithm of actions:

  1. Go to “Start” – “All Programs” – “Standard”.
  2. Right-click on the “Command line” item and select “Run as administrator”.
  3. In the window that appears, enter the regsvr32 / u d3dx9_43.dll command manually and press Enter.Enter the command and press Enter
  4. Enter the regsvr32 / i d3dx9_43.dll command and press Enter again.
  5. Close the command prompt window.After completing the registration of the library, close the command prompt

It is also recommended to restart your computer after these steps and try again to run the application that caused the error.

Deleting and restoring a library

If DirectX was previously installed on the PC, but during the automatic system update, there were any problems (for example, there was no Internet connection or the update process was interrupted), then this may lead to the fact that a simple solution to such a problem is to uninstall and repeat restoration of the library.

It is done as follows:

  1. Go to the directory C: \ Windows \ System32.Go to the System32 folder and locate the d3dx9_43.dll file
  2. Find the d3dx9_43.dll file, right-click on it and select “Delete” – it will be moved to the trash.
  3. Be sure to restart your computer.
  4. Open the “Recycle Bin”, find the file d3dx9_43.dll, right-click on it and select “Restore”.
  5. Restart your computer again.

A reboot is performed in order for Windows to scan system libraries – the system performs this action just at startup.

Cleaning the operating system registry

Also, problems in the registry cause this library. It is quite possible that the user tried to install DirectX several times and after each attempt there were records about the installer in the registry, but the set of APIs itself is not in the system. The same will be true if there were any errors during the DirectX update or the process was not completed.

The easiest way to clean your registry is to use the free CCleaner utility . You can download it from the official website (, you should choose the Free version.

After installing the program, do the following:

  1. Launch CCleaner from a shortcut on your desktop.
  2. Go to the “Registry” tab.Go to the “Registry” tab
  3. Click on “Search for problems”.
  4. Wait for the registry scan to complete.
  5. Select “Correct marked”.After cleaning the registry, it is imperative that you restart your computer.
  6. After finishing cleaning – restart the PC.

Updating Drivers

Windows 10 will automatically download any missing drivers and any future updates for them. So the owners of this OS just need to turn on the system update – then Windows will do everything itself.

But in older editions of Windows, you have to install and update drivers manually. A simpler option is to use special utilities to automatically find and install missing drivers. One of them is DriverDoc. You can download it from the official website (, but for its full operation you will need to purchase a license.

To update drivers using standard Windows tools, you will need:

  1. Click on the shortcut “My Computer” on the desktop or in the “Start” menu and select “Properties”.
  2. Select “Device Manager” on the left side of the window.
  3. In the list that appears, find your PC (as a rule, this is the first line of the list).
  4. Click on the line with the right mouse button and select “Update hardware configuration”.Draever update can be done through the device manager
  5. Wait until the system is scanned and new drivers are installed.
  6. Restart your PC.

Even if this does not help solve the problem with the error, you must constantly install the latest drivers for your PC. It is recommended to carry out this operation at least once every 2 – 3 months.

Download and install DirectX

If the above recommendations did not bring the desired effect or DirectX was not installed on the computer at all, then you should download this library and install it.

It should be downloaded exclusively from the official Microsoft website (

The library web installer will be saved to your computer. It is enough to launch it and follow the instructions on the screen. By the way, if the user has DirectX version 10, 11 or 12 installed, the installer will independently check which libraries are missing and install them automatically. After installation is complete, be sure to restart your PC.

The latest versions of DirectX independently check which libraries are in place and which are missing

This recommendation is relevant for all versions of Windows, including the outdated (and no longer supported by the manufacturer) XP. For the web installer to work, it is necessary to have access to the Internet, since during the installation process it will download all the missing libraries (on average, it will take from 10 to 20 megabytes of traffic, while the installer itself takes less than 1 Mb).

Video: d3dx9_43.dll error elimination

What to do to prevent the error from occurring again

To stop the error about the absence of the d3dx9_43.dll file on the computer, you should:

  • enable automatic system updates (the Windows Update service must also be running);
  • install DirectX using the web installer (it installs the latest version of the library);
  • use the built-in antivirus Windows Defender or Microsoft Security Essential;
  • regularly update the drivers of all installed devices (in particular, sound card and graphics adapter);
  • use only licensed software and Windows (for automatic updating to work, since this feature is absent or only partially functional on pirated copies of Windows).

There are many options for eliminating the error associated with the absence of the d3dx9_43.dll library. By following step-by-step instructions and recommendations, you can independently solve the problem and prevent it from recurring in the future.

by Abdullah Sam
I’m a teacher, researcher and writer. I write about study subjects to improve the learning of college and university students. I write top Quality study notes Mostly, Tech, Games, Education, And Solutions/Tips and Tricks. I am a person who helps students to acquire knowledge, competence or virtue.

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