Method 1: Installing the Rtnf3290.dll File to the Windows System Folder 

1. The file you downloaded is a compressed file with the extension ".zip". This file cannot be installed. To be able to install it, first you need to extract the dll file from within it. So, first double-click the file with the ".zip" extension and open the file.
2. You will see the file named "Rtnf3290.dll" in the window that opens. This is the file you need to install. Click on the dll file with the left button of the mouse. By doing this, you select the file.

   

3. Click on the "Extract To" button, which is marked in the picture. In order to do this, you will need the Winrar software. If you don't have the software, it can be found doing a quick search on the Internet and you can download it (The Winrar software is free).
4. After clicking the "Extract to" button, a window where you can choose the location you want will open. Choose the "Desktop" location in this window and extract the dll file to the desktop by clicking the "Ok" button.

   

5. Copy the "Rtnf3290.dll" file and paste it into the "C:\Windows\System32" folder.

   

6. If your operating system has a 64 Bit architecture, copy the "Rtnf3290.dll" file and paste it also into the "C:\Windows\sysWOW64" folder.

   NOTE! On 64 Bit systems, the dll file must be in both the "sysWOW64" folder as well as the "System32" folder. In other words, you must copy the "Rtnf3290.dll" file into both folders.

   

7. 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".

   

8. Paste the command below into the Command Line that will open up and hit Enter. This command will delete the damaged registry of the Rtnf3290.dll file (It will not delete the file we pasted into the System32 folder; it will delete the registry in Regedit. The file we pasted into the System32 folder will not be damaged).

   %windir%\System32\regsvr32.exe /u Rtnf3290.dll

   

9. 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 Rtnf3290.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 Rtnf3290.dll

   

10. 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 Rtnf3290.dll

    

11. 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 Rtnf3290.dll file that we deleted.

    %windir%\SysWoW64\regsvr32.exe /i Rtnf3290.dll

    

12. If you did the processes in full, the installation should have finished successfully. If you received an error from the command line, you don't need to be anxious. Even if the Rtnf3290.dll file was installed successfully, you can still receive error messages like these due to some incompatibilities. In order to test whether your dll problem was solved or not, try running the software giving the error message again. If the error is continuing, try the 2nd Method to solve this problem.

Method 2: Copying The Rtnf3290.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 "Rtnf3290.dll is missing", "Rtnf3290.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 Rtnf3290.dll file into this folder that opens.

   

4. This is all there is to the process. Now, try to run the software again. If the problem still is not solved, you can try the 3rd Method.

Method 3: Doing a Clean Install of the software That Is Giving the Rtnf3290.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 window will open up. Find the software that is giving you the dll error in this window that lists all the softwares on your computer and "Right-Click > Uninstall" on this software.

   

3. Uninstall the software from your computer by following the steps that come up 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 Rtnf3290.dll Error Using 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 Rtnf3290.dll Errors 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