By David Gewirtz
We often get Outlook-related questions from readers. Choosing which question to feature is usually a bit of a challenge, because we only have time to cover one of hundreds we get in each week. However, the question we're answering this week came from what you'd have to call a "priority reader" -- my wife.
Denise had uninstalled McAfee's antivirus program and had moved on to one from another vendor. Everything seemed to work fine, except for when she launched Outlook 2007. Whenever she launched Outlook, she got the message:
The Add-in "Outlook Scan" (scanotlk.dll) cannot be loaded and has been disabled by Outlook.
Outlook worked fine, but the message was annoying. And although she was willing to wait on a fix, I knew it was bothering her.
First, I looked in the Trust Center (the completely non-intuitive place add-on management had been moved). Scanotlk.dll wasn't listed there. It appeared to have have been completely removed.
Then I did the usual restart/shutdown dance. Still no indication of why the error kept coming up.
And, then, finally I remembered the DLL cache. Outlook uses a file called EXTEND.DAT to keep information on DLLs, including the path where they're located. Each time Outlook is run, it checks this file. And when you remove or add a new add-on, EXTEND.DAT is updated.
Or, at least, it's supposed to be. I wondered if perhaps the McAfee uninstaller hadn't bothered to update EXTEND.DAT.
The good news is that this is a safe file to delete. On Windows XP, it's located in:
On later Windows versions, it's located in:
To fix the problem, quit Outlook. Go to one of the above locations and find EXTEND.DAT, delete it, and restart Outlook.
There you go. No more warning message.
