Dan,
Many of our installations are single user and have just a single directory containing both the prg and data. Most of our customers with networks just have peer to peer. Each Workstation has its own copy of the exe that is updated from the master exe on the "server". Those that have real networks have the same setup. This arrangement is a hangover for DOS days, but to this point it has worked. Now, however, I am not sure.
A problem is a problem only as long as it has a possible solution. Lacking that, it becomes a FACT!