A note to people like me who floundered around trying to find out the source
of this error when running a macro.
I fiddled with DCOMCNFG and waded through server-side scripting kb articles
and interactive user stuff thinking I should go and slit my throat later...
(but first having a really fresh cup of hot coffee)

Then I saw something about a .dll corruption and went looking into
Tools|References.

Somehow, somewhere, two object libraries (Tools|References) listed were
checked as 'Missing'.  For me they were useless but perhaps had lingered
from an older installation of Word.   I unchecked them and they disappeared
from the list.
My macros then ran OK.

One was "Eyedog something or other"  which I vaguely recall I had installed
on another machine a few years back with  Word97. I had put OfficeXP on the
new machine and copied across my Normal template macros.
It seems the reference came across with the template macros - likely?
possible? - who knows ? - but they were there.