Right, a bit more info now I have tried a few different things. I have run the program reasonably successfully on my other PC (a laptop) which is running windows 98 and doesn't have Access installed. From this I have deduced that Access installation is not necessary. The problem I have with running this from the laptop is that it requires a higher resolution than my laptop can give (laptop best is 800 x 600) so I can't see the whole picture!
Some research on the SQL STATE code implies that the SQL installed in my modern XP machine cannot communicate with the older database of the program.
Can I and should I try to downgrade my SQL to an older version (from 2000 to version 7 perhaps)?