Method 1: Installing the Cmnprop.dll Library to the Windows System Directory 

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 dynamic link library from within it. So, first double-click the file with the ".zip" extension and open the file.
2. You will see the library named "Cmnprop.dll" in the window that opens. This is the library you need to install. Click on the dynamic link library with the left button of the mouse. By doing this, you select the library.

   

3. Click on the "Extract To" button, which is marked in the picture. In order to do this, you will need the Winrar program. If you don't have the program, it can be found doing a quick search on the Internet and you can download it (The Winrar program 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 dynamic link library to the desktop by clicking the "Ok" button.

   

5. Copy the "Cmnprop.dll" library and paste it into the "C:\Windows\System32" directory.

   

6. If your system is 64 Bit, copy the "Cmnprop.dll" library and paste it into "C:\Windows\sysWOW64" directory.

   NOTE! On 64 Bit systems, you must copy the dynamic link library to both the "sysWOW64" and "System32" directories. In other words, both directories need the "Cmnprop.dll" library.

   

7. In order to run the Command Line as an administrator, complete the following steps.

   NOTE! In this explanation, we ran the Command Line on Windows 10. If you are using one of the Windows 8.1, Windows 8, Windows 7, Windows Vista or Windows XP operating systems, you can use the same methods to run the Command Line as an administrator. Even though the pictures are taken from Windows 10, the processes are similar.

   1. First, open the Start Menu and before clicking anywhere, type "cmd" but do not press Enter.
   2. When you see the "Command Line" option among the search results, hit the "CTRL" + "SHIFT" + "ENTER" keys on your keyboard.
   3. A window will pop up asking, "Do you want to run this process?". Confirm it by clicking to "Yes" button.

   

8. Paste the command below into the Command Line window that opens and hit the Enter key on your keyboard. This command will delete the Cmnprop.dll library's damaged registry (It will not delete the file you pasted into the System32 directory, but will delete the registry in Regedit. The file you pasted in the System32 directory will not be damaged in any way).

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

   

9. If you are using a 64 Bit operating system, after doing the commands above, you also need to run the command below. With this command, we will also delete the Cmnprop.dll library's damaged registry for 64 Bit (The deleting process will be only for the registries in Regedit. In other words, the dll file you pasted into the SysWoW64 folder will not be damaged at all).

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

   

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

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

    

11. 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 Cmnprop.dll library that we deleted.

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

    

12. You may see certain error messages when running the commands from the command line. These errors will not prevent the installation of the Cmnprop.dll library. In other words, the installation will finish, but it may give some errors because of certain incompatibilities. After restarting your computer, to see if the installation was successful or not, try running the program that was giving the dll error again. If you continue to get the errors when running the program after the installation, you can try the 2nd Method as an alternative.

Method 2: Copying The Cmnprop.dll Library Into The Program Installation Directory 

1. First, you need to find the installation directory for the program you are receiving the "Cmnprop.dll not found", "Cmnprop.dll is missing" or other similar dll errors. In order to do this, right-click on the shortcut for the program and click the Properties option from the options that come up.

   

2. Open the program's installation directory by clicking on the Open File Location button in the Properties window that comes up.

   

3. Copy the Cmnprop.dll library into this directory that opens.

   

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

Method 3: Uninstalling and Reinstalling the Program That Is Giving the Cmnprop.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 programs installed on your computer in the list on this screen. Find the program 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 program. Confirm the process and wait for the uninstall process to finish. Restart your computer after the program has been uninstalled from your computer.

   

4. 4. After restarting your computer, reinstall the program that was giving you 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: Fixing the Cmnprop.dll Issue by Using the Windows System File Checker (scf scannow) 

1. In order to run the Command Line as an administrator, complete the following steps.

   NOTE! In this explanation, we ran the Command Line on Windows 10. If you are using one of the Windows 8.1, Windows 8, Windows 7, Windows Vista or Windows XP operating systems, you can use the same methods to run the Command Line as an administrator. Even though the pictures are taken from Windows 10, the processes are similar.

   1. First, open the Start Menu and before clicking anywhere, type "cmd" but do not press Enter.
   2. When you see the "Command Line" option among the search results, hit the "CTRL" + "SHIFT" + "ENTER" keys on your keyboard.
   3. A window will pop up asking, "Do you want to run this process?". Confirm it by clicking to "Yes" button.

   

2. Paste the command in the line below into the Command Line that opens up and press Enter key.

   sfc /scannow

   

3. The scan and repair process can take some time depending on your hardware and amount of system errors. Wait for the process to complete. After the repair process finishes, try running the program that is giving you're the error.

Method 5: Getting Rid of Cmnprop.dll Errors by Updating the Windows Operating System 

Some programs need updated dynamic link libraries. 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.

Windows Update Guides 

1. Windows Update Guide
2. Windows 8.1 and Windows 8 Update Guide
3. Windows 7 and Windows Vista Update Guide
4. Windows XP Update Guide