Method 1: Installing the Msdadiag.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 "Msdadiag.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 "Msdadiag.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 "Msdadiag.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 "Msdadiag.dll" file into both folders.

   

4. 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.

   

5. 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 Msdadiag.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 Msdadiag.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 Msdadiag.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 Msdadiag.dll

   

7. 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 Msdadiag.dll

   

8. Windows 64 Bit users must run the command below after running the previous command. With this command, we will create a clean and good registry for the Msdadiag.dll file we deleted.

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

   

9. You may see certain error messages when running the commands from the command line. These errors will not prevent the installation of the Msdadiag.dll file. 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 software that was giving the dll error again. If you continue to get the errors when running the software after the installation, you can try the 2nd Method as an alternative.

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

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

   

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

   

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

1. Press the "Windows" + "R" keys at the same time to open the Run tool. Paste the command below into the text field titled "Open" in the Run window that opens and press the Enter key on your keyboard. This command will open the "Programs and Features" tool.

   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. 4. After restarting your computer, reinstall the software that was giving you 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 Msdadiag.dll Error Using the Windows System File Checker 

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. Type the command below into the Command Line page that comes up and run it by pressing Enter on your keyboard.

   sfc /scannow

   

3. The process can take some time depending on your computer and the condition of the errors in the system. Before the process is finished, don't close the command line! When the process is finished, try restarting the software that you are experiencing the errors in after closing the command line.

Method 5: Solving the Msdadiag.dll Error by Updating Windows 

Some softwares require updated dll files from the operating system. If your operating system is not updated, this requirement is not met and you will receive dll errors. Because of this, updating your operating system may solve the dll errors you are experiencing.

Most of the time, operating systems are automatically updated. However, in some situations, the automatic updates may not work. For situations like this, you may need to check for updates manually.

For every Windows version, the process of manually checking for updates is different. Because of this, we prepared a special guide for each Windows version. You can get our guides to manually check for updates based on the Windows version you use through the links below.

Guides to Manually Update for All Windows Versions 

1. Guide to Manually Update Windows 10
2. Guide to Manually Update Windows 8.1 and Windows 8
3. Guide to Manually Update Windows 7 and Windows Vista
4. Guide to Manually Update Windows XP