The following is from an old version of the MSDN library, but may be what you need to know:

SYMPTOMS
When Automating Microsoft Word 2000 with Microsoft Visual Basic, you may receive the following error during a call to CreateObject or New:

Run-time error '-2147417846 (8001010a)':
Automation Error
When automating Word 2000 with Microsoft Visual C++, you might receive the following error when calling IClassFactory::CreateInstance:
Error (0x80010001): Call was rejected by callee. or CoCreateInstance:
Error (0x8001010A): The message filter indicated that the application is busy.

CAUSE
This error occurs on a system where Norton AntiVirus 2000 has been installed.
Microsoft Office 2000 supports AntiVirus plug-ins that can scan Office documents before they are opened. When the Norton AntiVirus plug-in is enabled on a system with Word 2000, you receive one of the messages above when trying to start Word through Automation.

RESOLUTION
To resolve the issue, remove the Norton AntiVirus plug-in for Microsoft Office 2000. To accomplish this, follow the steps below:

From the Start menu, click Run. Type the following command (including quotes) on the Run line (change the path to the file as needed):

regsvr32 /U "C:\Program Files\Norton AntiVirus\OfficeAV.dll"
Note that you receive a dialog box stating that the command succeeded.