If your Word mail merge main document connects to the database using DDE,
when Word opens the document, it will also open Access (if necessary).
Access will then open the database (if necessary).
To avoid opening /Access/, you have to connect using ODBC (most versions of
Word) or OLE DB (Word 2002 and later). In that case, Word still opens the
database using Jet (or ACE, in Word 2007), but it does not need to open
Access and you do not see any extra windows.
However, there are reasons why your Word document may need to connect via
DDE, including:
a. it connects to a parameter query and the user needs to enter a parameter
b. it connects to a query that uses old-style "wildcard characters" * and ?
rather than the ANSI wildcards % and _
c. it connects to a query that uses a user defined Access VBA function, or
some other functions that do not work with ODBC/OLE DB
....and so on.You may also find that DDE has been used because of text
truncation problems etc.
However, if you do not need DDE (and I think you can only really tell by
experimenting), to change the connection method, check
Word->Tools->Options->general-->Confirm conversions at open (Word 2003 and
earlier) or click the Office button, then check Word
Options->Advanced->General->Confirm File format conversion on open. Then go
through the connection proces again.