Method 1: Solving the DLL Error by Copying the Libfftw3f.dll File to the Windows System Folder 

1. The file you are going to download is a compressed file with the ".zip" extension. You cannot directly install the ".zip" file. First, you need to extract the dll file from inside it. So, double-click the file with the ".zip" extension that you downloaded and open the file.
2. You will see the file named "Libfftw3f.dll" in the window that opens up. This is the file we are going to install. Click the file once with the left mouse button. By doing this you will have chosen the file.

   

3. Click the "Extract To" symbol marked in the picture. To extract the dll file, it will want you to choose the desired location. Choose the "Desktop" location and click "OK" to extract the file to the desktop. In order to do this, you need to use the Winrar software. If you do not have this software, you can find and download it through a quick search on the Internet.

   

4. Copy the "Libfftw3f.dll" file you extracted and paste it into the "C:\Windows\System32" folder.

   

5. If your system is 64 Bit, copy the "Libfftw3f.dll" file and paste it into "C:\Windows\sysWOW64" folder.

   NOTE! On 64 Bit systems, you must copy the dll file to both the "sysWOW64" and "System32" folders. In other words, both folders need the "Libfftw3f.dll" file.

   

6. First, we must run the Windows Command Prompt as an administrator.

   NOTE! We ran the Command Prompt on Windows 10. If you are using Windows 8.1, Windows 8, Windows 7, Windows Vista or Windows XP, you can use the same methods to run the Command Prompt as an administrator.

   1. Open the Start Menu and type in "cmd", but don't press Enter. Doing this, you will have run a search of your computer through the Start Menu. In other words, typing in "cmd" we did a search for the Command Prompt.
   2. When you see the "Command Prompt" option among the search results, push the "CTRL" + "SHIFT" + "ENTER
   " keys on your keyboard.
   3. A verification window will pop up asking, "Do you want to run the Command Prompt as with administrative permission?" Approve this action by saying, "Yes".

   

7. Let's copy the command below and paste it in the Command Line that comes up, then let's press Enter. This command deletes the Libfftw3f.dll file's problematic registry in the Windows Registry Editor (The file that we copied to the System32 folder does not perform any action with the file, it just deletes the registry in the Windows Registry Editor. The file that we pasted into the System32 folder will not be damaged).

   %windir%\System32\regsvr32.exe /u Libfftw3f.dll

   

8. If you have a 64 Bit operating system, after running the command above, you must run the command below. This command will clean the Libfftw3f.dll file's damaged registry in 64 Bit as well (The cleaning process will be in the registries in the Registry Editor< only. In other words, the dll file you paste into the SysWoW64 folder will stay as it).

   %windir%\SysWoW64\regsvr32.exe /u Libfftw3f.dll

   

9. In order to cleanly recreate the dll file's registry that we deleted, copy the command below and paste it into the Command Line and hit Enter.

   %windir%\System32\regsvr32.exe /i Libfftw3f.dll

   

10. If the Windows version you use has 64 Bit architecture, after running the command above, you must run the command below. With this command, you will create a clean registry for the problematic registry of the Libfftw3f.dll file that we deleted.

    %windir%\SysWoW64\regsvr32.exe /i Libfftw3f.dll

    

11. If you did all the processes correctly, the missing dll file will have been installed. You may have made some mistakes when running the Command Line processes. Generally, these errors will not prevent the Libfftw3f.dll file from being installed. In other words, the installation will be completed, but it may give an error due to some incompatibility issues. You can try running the program that was giving you this dll file error after restarting your computer. If you are still getting the dll file error when running the program, please try the 2nd method.

Method 2: Copying The Libfftw3f.dll File Into The Software File Folder 

1. In order to install the dll file, you need to find the file folder for the software that was giving you errors such as "Libfftw3f.dll is missing", "Libfftw3f.dll not found" or similar error messages. In order to do that, Right-click the software's shortcut and click the Properties item in the right-click menu that appears.

   

2. Click on the Open File Location button that is found in the Properties window that opens up and choose the folder where the application is installed.

   

3. Copy the Libfftw3f.dll file.
4. Paste the dll file you copied into the software's file folder that we just opened.

   

5. When the dll file is moved to the software file folder, it means that the process is completed. Check to see if the problem was solved by running the software giving the error message again. If you are still receiving the error message, you can complete the 3rd Method as an alternative.

Method 3: Doing a Clean Reinstall of the Software That Is Giving the Libfftw3f.dll Error 

1. Push the "Windows" + "R" keys at the same time to open the Run window. Type the command below into the Run window that opens up and hit Enter. This process will open the "Programs and Features" window.

   appwiz.cpl

   

2. The softwares listed in the Programs and Features window that opens up are the softwares installed on your computer. Find the software that gives you the dll error and run the "Right-Click > Uninstall" command on this software.

   

3. Following the instructions that come up, uninstall the software from your computer and restart your computer.

   

4. After restarting your computer, reinstall the software that was giving the error.
5. This method may provide the solution to the dll error you're experiencing. If the dll error is continuing, the problem is most likely deriving from the Windows operating system. In order to fix dll errors deriving from the Windows operating system, complete the 4th Method and the 5th Method.

Method 4: Solving the Libfftw3f.dll error with the Windows System File Checker 

1. First, we must run the Windows Command Prompt as an administrator.

   NOTE! We ran the Command Prompt on Windows 10. If you are using Windows 8.1, Windows 8, Windows 7, Windows Vista or Windows XP, you can use the same methods to run the Command Prompt as an administrator.

   1. Open the Start Menu and type in "cmd", but don't press Enter. Doing this, you will have run a search of your computer through the Start Menu. In other words, typing in "cmd" we did a search for the Command Prompt.
   2. When you see the "Command Prompt" option among the search results, push the "CTRL" + "SHIFT" + "ENTER
   " keys on your keyboard.
   3. A verification window will pop up asking, "Do you want to run the Command Prompt as with administrative permission?" Approve this action by saying, "Yes".

   

2. After typing the command below into the Command Line, push Enter.

   sfc /scannow

   

3. Depending on your computer's performance and the amount of errors on your system, this process can take some time. You can see the progress on the Command Line. Wait for this process to end. After the scan and repair processes are finished, try running the software giving you errors again.

Method 5: Fixing the Libfftw3f.dll Error by Manually Updating Windows 

Some softwares need updated dll files. When your operating system is not updated, it cannot fulfill this need. In some situations, updating your operating system can solve the dll errors you are experiencing.

In order to check the update status of your operating system and, if available, to install the latest update packs, we need to begin this process manually.

Depending on which Windows version you use, manual update processes are different. Because of this, we have prepared a special article for each Windows version. You can get our articles relating to the manual update of the Windows version you use from the links below.

Explanations on Updating Windows Manually 

1. Explanation on Updating Windows 10 Manually
2. Explanation on Updating Windows 8.1 and Windows 8 Manually
3. Explanation on Updating Windows 7 and Windows Vista Manually
4. Explanation on Updating Windows XP Manually