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

   

4. 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".

   

5. Paste the command below into the Command Line that will open up and hit Enter. This command will delete the damaged registry of the Mda leslie.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 Mda leslie.dll

   

6. If you have a 64 Bit operating system, after running the command above, you must run the command below. This command will clean the Mda leslie.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 Mda leslie.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 Mda leslie.dll

   

8. 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 Mda leslie.dll file that we deleted.

   %windir%\SysWoW64\regsvr32.exe /i Mda leslie.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 Mda leslie.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 Mda leslie.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 "Mda leslie.dll is missing", "Mda leslie.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 Mda leslie.dll file into the folder we opened up.

   

4. That's all there is to the installation process. Run the software giving the dll error again. If the dll error is still continuing, completing the 3rd Method may help solve your problem.

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

1. Open the Run tool by pushing the "Windows" + "R" keys found on your keyboard. Type the command below into the "Open" field of the Run window that opens up and press Enter. 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. After restarting your computer, reinstall the software that was giving the error.
5. You can solve the error you are expericing with this method. If the dll error is continuing in spite of the solution methods you are using, the source of the problem is the Windows operating system. In order to solve dll errors in Windows you will need to complete the 4th Method and the 5th Method in the list.

Method 4: Solving the Mda leslie.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. 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 software that is giving you're the error.

Method 5: Fixing the Mda leslie.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.

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