ESET Outlook Plugin error when starting Microsoft Outlook

KB Solution ID: SOLN767|Last Revised: January 28, 2014

Issue

  • you receive the following error message when starting Microsoft Outlook:

    The Add-in 'ESET Outlook Plugin' (C:\PROGRA~1\ESET\ESETNO~1\EPLGOU~1.DLL) cannot be loaded and has been disabled by Outlook. If no update is available, please uninstall the Add-in.
     
  • The error message above may occur on a computer with multiple user profiles after an upgrade, reinstall, or failed uninstall of ESET Smart Security.

Solution

Click your operating system below to view the corresponding solution

Windows XP | Windows Vista
| Windows 7 | Windows 8


Windows XP

  1. Exit Outlook.
     
  2. Click Start Search All files and Folders More advanced options and select the Search hidden files and folders check box.
     
  3. In the top search field, type extend.dat and click Search.
     
  4. In the search results section, right-click on the extend.dat file and click Delete.
    • If Outlook is used by multiple profiles, an extend.dat file exists for each profile. Repeat the procedure above for each profile to restore functionality to Outlook. By default this file is located in C:\Documents and Settings\Username\Local Settings\Application Data\Microsoft\Outlook

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Windows Vista

  1. Exit Outlook.
     
  2. Click Start and type extend.dat in the bottom search field then click the search icon.
     
  3. Click Advanced Search in the upper right corner. Select the Include non-indexed, hidden, and system files (might be slow) check box on the left. On the right, type extend.dat in the Name field and click the Search button.
     
  4. In the search results section, right-click on the extend.dat file and click Delete.
    • If Outlook is used by multiple profiles, an extend.dat file exists for each profile. Repeat the procedure above for each profile to restore functionality to Outlook. By default this file is located in C:\Users\Username\AppData\Local\Microsoft\Outlook

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Windows 7

Solution 1: Delete "extend.dat"

  1. Exit Outlook.
     
  2. Click Start and type Search in the bottom search field then click the search icon.
     
  3. Click Change search options for files and folders.
     
  4. Click the View tab and select Show hidden files, folders, and drives. Deselect Hide extensions for known file types and Hide protected operating system files.
     
  5. Click Apply and OK.
     
  6. Click Start and type extend.dat in the bottom search field then click the search icon.
     
  7. In the search results section, right-click on the extend.dat file and click Delete.
    • If Outlook is used by multiple profiles, an extend.dat file exists for each profile. Repeat the procedure above for each profile to restore functionality to Outlook. By default this file is located in C:\Users\Username\AppData\Local\Microsoft\Outlook


Solution 2:
Outlook 2003 only–Install Office 2003 Service Pack 3

If you are using Microsoft Outlook 2003, you can install Office 2003 Service Pack 3 to resolve the error message. Office 2003 Service Pack 3 can be downloaded from Microsoft’s website, here:

http://www.microsoft.com/downloads/details.aspx?FamilyId=E25B7049-3E13-433B-B9D2-5E3C1132F206&displaylang=en

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Windows 8

Solution 1: Delete "extend.dat"

  1. Exit Outlook.
     
  2. Press the Windows key+ F to search for files, type "Search" into the search bar and then click Settings.
     
  3. Click Change search options for files and folders.
     
  4. Select the View tab, select Show hidden files, folders and drives, click Apply and then click OK.
     
  5. Press the Windows key+ F to search for files and type "extend.dat" into the search bar.
     
  6. Click extend.dat and then click Go to file location at the bottom of the screen.
     
  7. Right-click on the extend.dat file and select Delete.
    • If Outlook is used by multiple profiles, an extend.dat file exists for each profile. Repeat the procedure above for each profile to restore functionality to Outlook. By default this file is located in C:\Users\Username\AppData\Local\Microsoft\Outlook
       

Solution 2: Outlook 2003 only–Install Office 2003 Service Pack 3

 If you are using Microsoft Outlook 2003, you can install Office 2003 Service Pack 3 to resolve the error message. Office 2003 Service Pack 3 can be downloaded from Microsoft’s website, here:

http://www.microsoft.com/downloads/details.aspx?FamilyId=E25B7049-3E13-433B-B9D2-5E3C1132F206&displaylang=en

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