NB, despite the name of this group in Microsoft COmmunities, in usenet it's
called "microsoft.public.word.mailmerge.fields" and there's no mention of
fax. So you may be better off asking in, e.g.
microsoft.public.windows.vista.print_fax_scan

My /guess/ is that what this message is telling you is that
a. when you set up Microsoft Fax and Scan, you specify a folder where it
holds its "Fax Archive" - the Inbox and Sent Items
b. you either haven't set that up (perhaps you haven't actually used
Windows Fax and Scan before), or the folder you specified when you set it up
is no longer there, or is no longer accessible to you.

If you haven't actually used Fax and Scan before, I suggest you open it up
and see if it offers to go through a configuration sequence. If not, have a
look in its Tools|Settings|Advanced tab.

If it isn't that, I doubt if I can offer any more help as my Vista system is
not really set up to send faxes via that mechanism at present, but just out
of interest, what menu option in Word are you using to send your fax? Here,
I would have to choose Office Button->Print->Print, then select a suitable
fax printer.

Peter Jamieson