Method 1: Copying the Agt0405.dll File to the Windows System Folder 

1. The file you downloaded is a compressed file with the ".zip" extension. In order to install it, first, double-click the ".zip" file and open the file. You will see the file named "Agt0405.dll" in the window that opens up. This is the file you need to install. Drag this file to the desktop with your mouse's left button.

   

2. Copy the "Agt0405.dll" file you extracted and paste it into the "C:\Windows\System32" folder.

   

3. If you are using a 64 Bit operating system, copy the "Agt0405.dll" file and paste it into the "C:\Windows\sysWOW64" as well.

   NOTE! On Windows operating systems with 64 Bit architecture, the dll file must be in both the "sysWOW64" folder as well as the "System32" folder. In other words, you must copy the "Agt0405.dll" file into both folders.

   

4. In order to complete this step, you must run the Command Prompt as administrator. In order to do this, all you have to do is follow the steps below.

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

   1. Open the Start Menu and before clicking anywhere, type "cmd" on your keyboard. This process will enable you to run a search through the Start Menu. We also typed in "cmd" to bring up the Command Prompt.
   2. Right-click the "Command Prompt" search result that comes up and click the Run as administrator" option.

   

5. Paste the command below into the Command Line window that opens up and press Enter key. This command will delete the problematic registry of the Agt0405.dll file (Nothing will happen to the file we pasted in the System32 folder, it just deletes the registry from the Windows Registry Editor. The file we pasted in the System32 folder will not be damaged).

   %windir%\System32\regsvr32.exe /u Agt0405.dll

   

6. If the Windows you use has 64 Bit architecture, after running the command above, you must run the command below. This command will clean the broken registry of the Agt0405.dll file from the 64 Bit architecture (The Cleaning process is only with registries in the Windows Registry Editor. In other words, the dll file that we pasted into the SysWoW64 folder will stay as it is).

   %windir%\SysWoW64\regsvr32.exe /u Agt0405.dll

   

7. You must create a new registry for the dll file that you deleted from the registry editor. In order to do this, copy the command below and paste it into the Command Line and hit Enter.

   %windir%\System32\regsvr32.exe /i Agt0405.dll

   

8. If you are using a 64 Bit operating system, after running the command above, you also need to run the command below. With this command, we will have added a new file in place of the damaged Agt0405.dll file that we deleted.

   %windir%\SysWoW64\regsvr32.exe /i Agt0405.dll

   

9. 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 Agt0405.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 Agt0405.dll File Into The Software File Folder 

1. First, you must find the installation folder of the software (the software giving the dll error) you are going to install the dll file to. In order to find this folder, "Right-Click > Properties" on the software's shortcut.

   

2. Open the software file folder by clicking the Open File Location button in the "Properties" window that comes up.

   

3. Copy the Agt0405.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: Uninstalling and Reinstalling the Software that Gives You the Agt0405.dll Error 

1. Open the Run window by pressing the "Windows" + "R" keys on your keyboard at the same time. Type in the command below into the Run window and push Enter to run it. This command will open the "Programs and Features" window.

   appwiz.cpl

   

2. The Programs and Features screen will come up. You can see all the softwares installed on your computer in the list on this screen. Find the software giving you the dll error in the list and right-click it. Click the "Uninstall" item in the right-click menu that appears and begin the uninstall process.

   

3. A window will open up asking whether to confirm or deny the uninstall process for the software. Confirm the process and wait for the uninstall process to finish. Restart your computer after the software has been uninstalled from your computer.

   

4. After restarting your computer, reinstall the software that was giving the error.
5. This process may help the dll problem you are experiencing. If you are continuing to get the same dll error, the problem is most likely with Windows. In order to fix dll problems relating to Windows, complete the 4th Method and 5th Method.

Method 4: Solving the Agt0405.dll Error Using the Windows System File Checker 

1. In order to complete this step, you must run the Command Prompt as administrator. In order to do this, all you have to do is follow the steps below.

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

   1. Open the Start Menu and before clicking anywhere, type "cmd" on your keyboard. This process will enable you to run a search through the Start Menu. We also typed in "cmd" to bring up the Command Prompt.
   2. Right-click the "Command Prompt" search result that comes up and click the Run as administrator" option.

   

2. Paste the command below into the Command Line that opens up and hit the Enter key.

   sfc /scannow

   

3. This process can take some time. You can follow its progress from the screen. Wait for it to finish and after it is finished try to run the software that was giving the dll error again.

Method 5: Fixing the Agt0405.dll Errors by Manually Updating Windows 

Most of the time, softwares have been programmed to use the most recent dll files. If your operating system is not updated, these files cannot be provided and dll errors appear. So, we will try to solve the dll errors by updating the operating system.

Since the methods to update Windows versions are different from each other, we found it appropriate to prepare a separate article for each Windows version. You can get our update article that relates to your operating system version by using 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