Method 1: Copying the W2k_lsa_auth.dll File to the Windows System Folder 

1. The file you are going to download is a compressed file with the ".zip" extension. You cannot directly install the ".zip" file. First, you need to extract the dll file from inside it. So, double-click the file with the ".zip" extension that you downloaded and open the file.
2. You will see the file named "W2k_lsa_auth.dll" in the window that opens up. This is the file we are going to install. Click the file once with the left mouse button. By doing this you will have chosen the file.

   

3. Click the "Extract To" symbol marked in the picture. To extract the dll file, it will want you to choose the desired location. Choose the "Desktop" location and click "OK" to extract the file to the desktop. In order to do this, you need to use the Winrar software. If you do not have this software, you can find and download it through a quick search on the Internet.

   

4. Copy the "W2k_lsa_auth.dll" file you extracted and paste it into the "C:\Windows\System32" folder.

   

5. If you are using a 64 Bit operating system, copy the "W2k_lsa_auth.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 "W2k_lsa_auth.dll" file into both folders.

   

6. 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.

   

7. 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 W2k_lsa_auth.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 W2k_lsa_auth.dll

   

8. 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 W2k_lsa_auth.dll file'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 W2k_lsa_auth.dll

   

9. We need to make a clean registry for the dll file's registry that we deleted from Regedit (Windows Registry Editor). In order to accomplish this, copy and paste the command below into the Command Line and press Enter key.

   %windir%\System32\regsvr32.exe /i W2k_lsa_auth.dll

   

10. If you are using a Windows with 64 Bit architecture, after running the previous command, you need to run the command below. By running this command, we will have created a clean registry for the W2k_lsa_auth.dll file (We deleted the damaged registry with the previous command).

    %windir%\SysWoW64\regsvr32.exe /i W2k_lsa_auth.dll

    

11. 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 W2k_lsa_auth.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 W2k_lsa_auth.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 "W2k_lsa_auth.dll is missing", "W2k_lsa_auth.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 W2k_lsa_auth.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 W2k_lsa_auth.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 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.
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 W2k_lsa_auth.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. 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 W2k_lsa_auth.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.

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