Problem: After upgrading from VirusScan 4.5.1 to VirusScan Enterprise 7, Microsoft Outlook begins displaying an error message on startup that \“The addin \’C:\\Program Files\\McAfee\\VirusScan\\scanemal.dll\‘ could not be installed or loaded.\“
Solution: Exit Outlook. Find and delete the file EXTEND.DAT. Reopen Outlook; the problem should have gone away.
Explanation: For some reason, Outlook caches all its Registry settings in EXTEND.DAT so it doesn\’t have to look in the Registry. Problem is, if the Registry changes, Outlook doesn\’t know about it. Deleting EXTEND.DAT forces Outlook to look everything up in the Registry again.