d3dx9_40.dll is missing or not designed to work on Windows

The error “falta d3dx9_40.dll” usually appears when the user tries to open an application or a game that needs this DLL file (dynamic link library) in particular.

After going through most of the cases that affected users have reported, We conclude that there are two types of error messages associated with the d3dx9_40.dll file:

• The program cannot start because d3dx9_40.dll is missing from your computer. Try reinstalling the program to fix this problem.

• C: N-System Windows32d3dx9_40.dll is not designed to work on Windows or contains an error. Try installing the program again using the original installation media or contact your system administrator or software vendor for help.

Although the two error messages look different, the main cause is usually the same. The vast majority of these errors will occur because the application in question cannot call the d3dx9_40.dll file.. This is because it is missing from the system or because it is corrupted.

Most of the time, Errors related to the d3dx9_40.dll file are reported when the user tries to open an older game that uses optional DLL files included in the DirectX distribution 9.

What is d3dx9_40.dll?

The d3dx9_40.dll file is just a small part of the many DLL files contained in Microsoft DirectX software distribution packages.. Each DLL file (Dynamic link library) contains specific functionality that other third-party programs may use. This allows multiple programs to share functionality that is rooted in a single file.

Please note that the d3dx9_40.dll file is part of an optional DirectX update 9 which is not present by default in Windows 8 o Windows 10 (it is also not installed via Windows Update).

Warning: Downloading an individual d3dx9_40.dll file from a DLL download site is not recommended. Often, users who took this shortcut found that the so-called quick fix actually ended up producing a different error message. What's more, security researchers argue that some of these individually hosted DLL files could contain malicious code designed to expose the system to future virus infections. The best way to solve this problem is to only follow the methods that adhere to the official channels (like the ones listed below).

How to repair errors associated with d3dx9_40.dll

If you are looking for a workable solution for an error associated with d3dx9_40.dll, start to fix the problem with the following methods. Users who managed to solve the problem after encountering a similar situation confirm that the two methods listed below work. Follow the two possible solutions in order until you find a method that solves the problem..

Method 1: install DirectX end-user runtimes

Most of the users who have had problems with an error associated with the d3dx9_40.dll file have managed to resolve the problem quickly by installing DirectX End-User Runtimes..

Unless your system is experiencing underlying damage, The steps below should resolve any issues caused by the d3dx9_40.dll file:

1. Visit this official Microsoft link (here) and download the installer for DirectX End-User Runtimes.

   

2. Once the download is complete, open the installer and follow the onscreen instructions to install the optional DirectX update 9.

3. After the installation is complete, restart your computer and see if the problem has been resolved by opening the application that previously displayed the d3dx9_40.dll error.

If you still have the same problem, go to Method 2.

Method 2: remove or rename the corrupted d3dx9_40.dll

If the first method did not solve the problem, it is very likely that some damage is preventing the d3dx9_40.dll file from being replaced with a fresh copy. Fortunately, some users facing the same problem found a pretty easy solution.

This method consists of removing the actively used d3dx9_40.dll file from all locations that Windows uses to call it. If the corrupted file refuses to be removed, we will rename the DLL file using the executable .old, essentially telling Windows to treat it as an outdated version.

Here is a quick guide (with screenshots) to remove all active occurrences of d3dx9_40.dll and then reinstall the DirectX redistor:

1. In File Explorer, navigate to C: Windows N-System32. In the System folder 32, use the search function or navigate to the location of the d3dx9_40.dll manually. Once i find it, right click on it and choose Delete.

   Note: If delete it shows a different error, let's change the name with the extension .old. To do this, right click on the d3dx9_40.dll file and choose Rename, and then just add the ending .old to the end of the name. This will instruct your operating system to ignore this file, which will allow you to install a new copy later.

   

2. Once the first location has been resolved, go to C: Windows ~ SysWOW64 and reflect the same procedure we did in step 1. After deleting or renaming the d3dx9_40.dll file, you can close File Explorer.

3. Now we are going to fill in the gaps and replace the damaged d3dx9_40.dll file with a fresh copy. To do this, visit this link (here), descargue DirectX End-User Runtimes, open the installer and follow the onscreen instructions to install it again.

   

4. Once the missing DLL file has been installed via the end-user installer, reboot your system. In the next start, you should be able to open the application without the d3dx9_40.dll error.