Yes that method will work......but only if the user knows *exactly*
which files to copy.....there could be config type files, link files etc
besides the database files that need to be also transfered to keep his
files in sync with the main software program.

A better way a user could do it is, after installing the external
harddrive, tell the program to save any old files currently currently
accessible on his C: drive to the new drive.....that way, his program
knows where the files have been relocated to.......but this method will
only work **** if **** his program allows saving and/or subsequent
reading a different location than the current working sub/directory that
the program is installed in.  Depending on how old the software is,
version #, running in previous Windows emulation mode or old DOS program
mode etc....there was no way to tell, IIRC, from his initial message.

To my mind, a far better course of action, as I and Malke, suggested to
the poster, is to explore the software's website for FAQ's, support and
to avail himself of the community there so he can actually get advice
from potential community participants on how to proceed with obtaining
the results he's looking for.

Anyways, these were just some of the things running through ma old grey
cells while I read his message........YMMV.  :-)