Fix The Outlook Error 0x80040154 Using These 4 Proven Solutions

The Outlook error code 0x80040154 usually signals a problem with a missing component or unregistered part in the Windows operating system or Microsoft Outlook. This error message is often associated with a "Class not registered" message. This signifies that a Dynamic Link Library (DLL) or other component needed by the Outlook application is missing, not registered, or, in some cases, corrupt.

The possible reasons are virus infection or a spyware attack, installing multiple unreliable third-party applications and add-ins in Outlook, and oversized PST files. Irrespective of what might have triggered the issue. This article is here to help you resolve the Outlook error number 0x80040154.

How To Fix the Outlook Error 0x80040154?

Method 1: Re-register DLL Files

DLL files are absolutely essential for Outlook's correct functioning. If these files become corrupt, missing, or unregistered, Outlook will not function properly.

Depending on what has happened to your DLL files. You can either run an SFC scan to repair corrupt DLL files. You can download them from a reliable source or re-register them if they are missing. You can also reinstall the application to fix the issue.

More on that later on.

Method 2: Disable Outlook Add-ins

Installing various third-party add-ins can trigger various Outlook errors, including the 0x80040154 error. These add-ins cause conflict and interfere with normal Outlook operations and tasks.

Therefore, you can disable the add-ins or completely remove the problematic ones.

You can try starting Outlook normally. If the error prevents you from starting or using the application, you can try booting the application in Safe Mode.

  1. Hit the Win + R key to open the Run dialog box.
  2. Type outlook.exe in the search bar and click on OK or hit the Enter button.
  3. See if the error persists. If you can run the application without any problems, then the add-in is definitely to blame.

  4. Go to File > Options > Add-ins.
  5. In the Add-ins window, go to the bottom of the window, ensure the COM Add-ins option is selected, and click on the Go button.
  6. Uncheck all the add-ins and click on the OK button.
  7. Restart the Outlook.
  8. You can now try re-enabling each add-in one at a time. If the error re-appears after you have enabled specific add-ins. You can either uninstall and reinstall the problematic add-in or update it.

The next solution in this list is especially helpful in case your PST files have gotten corrupt.

Method 3: Repair Outlook PST File To Fix the Outlook Error 0x80040154

Use Outlook PST repair software to fix the PST file that generates Outlook error 0x80040154 on a Windows PC. With a simple graphical user interface, even a novice can repair a corrupted Outlook PST file showing Outlook error 0x80040154 or any other error message.

This application does not modify the original PST file during the repair process; rather, it reads data from a corrupt PST file to a newly created PST file and fixes issues in it, ensuring no alteration is done to the original PST file.

This Outlook PST repair program effectively fixes MS Outlook PST on Microsoft Outlook 2000, 2002, 2003, 2007, 2010, and 2013 versions. Yodot Outlook PST Repair can be easily installed on many Windows operating systems, including Windows XP, Windows Vista, Windows Server 2003, Windows Server 2008, Windows 7, and Windows 8.

Simple to fix PST File Using Yodot

  1. Download and install Yodot Outlook PST Repair software in the system by logging in as the local system admin. Upon completion of the installation process, you can view the cut icon on the desktop.
  2. Launch the application and follow the instructions provided on the tool's main screen.
  3. Select “Open PST File” if the location of the PST file is known.
  4. If you don’t know where the PST file is on your PC, click the “Find PST File” option.
  5. Finally, if your computer has different Outlook profiles, click “Select Outlook Profile” to select a particular Outlook PST file.
  6. Select the PST file and then hit the Next button to proceed to the next screen. Depending on the severity of the PST file damage, you can select the Normal Scan or Smart Scan option.
  7. After selecting the scan option, find the destination location to save the PST file and click the Repair button.
  8. As soon as the repair process is completed, the contents of the repaired PST file can be viewed.

If you think there’s no issue with your Outlook’s PST file. I recommend you try reinstalling Outlook.

Method 4: Reinstall Outlook

Reinstalling the Outlook application can be the ultimate solution to help you fix Outlook Error 0x80040154. This solution addresses several issues, such as corrupt files, missing DLL files, improper or incorrect Registry Entries, conflicting settings, and compatibility issues with Outlook and the Operating system that might be causing the error.

Steps to Reinstall the Outlook Application

1: You first need to uninstall the installed version of Microsoft Outlook. Since Microsoft Outlook is a part of the Microsoft Office suite, you need to uninstall the Office application.

2: Open the Control Panel and find and click on the Programs and Features option.

3: Find the Microsoft Office application in the list. Right-click on it, and click on the Uninstall option from the menu.

4: Follow the on-screen instructions to complete the process.

5: Delete any remaining files and residuals. Go to the following location. "C:\Program Files\Microsoft Office" and delete the folder(s) if they still reside on your system.

6: The next step in this list is to delete the registry entries linked to your Office application.

7: Press the Win + R keys, type "regedit," click on the OK button, and hit the Enter key.

8: Navigate to the following location, "HKEY_CURRENT_USERSoftwareMicrosoftOffice," right-click on the Office folder, and click the delete button.

You have completed completely uninstalling the Office application. The next thing you should do is reinstall the Microsoft Office application.

9: Use the Office installation media or download a fresh copy from the Microsoft website. Then, follow the on-screen instructions to install the application.

10: Once the application is installed on your system, launch the Office application and follow the prompts to activate the product using the product key or the Office 365 subscription.

Method 5: Update Windows

Updating to a newer or latest version of the Windows OS can also help you fix the 0x80040154 error in Outlook.

Upgrading the OS can be helpful, especially if your system files have become corrupt or outdated. It can also help you with issues related to the DLL files and resolve compatibility issues between the Outlook application and the Windows system. Update security patches and fix bugs and glitches.

1: Hit the Windows + I keys to open the Settings window.

2: Navigate to the Windows Update or Update and Security option.

3: Click on the "Check for updates" option. Windows will start searching for any pending updates.

4: If any fresh updates are available. Windows will ask you to update.

5: Click on the "Download" button, followed by clicking on the Install option. This will start the OS updating process.

6: Once the process is complete. Restart your system to let the changes take effect.

7: Launch the Outlook application and see if the troubling error has been resolved or not.


This brings us to the end of our long discussion on fixing error code 0x80040154. We have discussed this error, why it occurs (namely virus or malware attacks, incorrect DLL files, corrupt PST files, problematic add-ins, etc.), and various ways to fix it, such as repairing the DLL files, disabling add-ins, repairing the corrupt or damaged PST files using the Yodot Outlook PST Repair, reinstalling the Outlook application, and updating Windows OS, etc. Are all tried and tested to help you fix the issue.

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