"The add-in cannot be loaded and has been disabled by Outlook"
Outlook is firm about its disabling that add-in of which, it seems, you should rid yourself. You've tried, of course, uninstalling the application behind the Outlook extension — but to no avail.
Outlook isn't much help in letting you know where to uninstall the disabled add-on either, or any add-in for that matter. Fortunately, it is but a short tour with a somewhat unexpected twist that takes you to the place where add-ons reside in Outlook. Trust it.
Uninstall an Outlook Add-On
To completely remove a plug-in from Outlook:
- Select Tools | Trust Center... from the menu in Outlook.
- Go to the Add-ins category.
- Select either COM Add-ins or Exchange Client Extensions, depending on the type of add-in you want to remove under Manage.
- You can see each extension's type in the Type column.
- Click Go....
- If the add-on you want to remove is a COM add-in:
- Highlight the extension you want to delete.
- Click Remove.
- If the add-on you want to delete is an Exchange client extension:
- Make sure the add-in you want to remove is not checked in the list.
- Click OK.
Outlook Still Thinks The Broken Add-On is Somewhere?
If Outlook complains about an extension you can find in none of the add-in manager's lists, you can try deleting Outlook's add-in cache:
- Make sure Outlook is not running.
- Press Windows-R.
- Type "%localappdata%\Microsoft\Outlook" (not including the quotation marks).
- Using Windows 2000 or XP, use "%appdata%\Microsoft\Outlook" instead.
- Click OK.
- Highlight the "extend.dat" file.
- Press Del.
Should you run into more problems starting Outlook now than you had before, restore "extend.dat" from the trash. You can select Edit | Undo Delete right in the Explorer window in which you trashed the file.