Dear Cotswold:
What happens if you move any DBF files you access to something that is NOT in the root of your C drive? Say start your application in your "Documents" folder (or a subdirectory under there), with the DBFs there. Does it work then?
Micro$haft has long deprecated applications having direct access to anything that is on the C drive and not in the User's own directory. So it may or may not have something to do with that.
David A. Smith