>On a network, when the second user logs on to my program, he or she gets the message "access denied". I've set the exe attribute to read-only. What else should I do?

It's likely that both systems are trying to use the same FOXUSER resource file; under most conditions, it is opened exclusively by VFP. There are several workarounds:

(1) If you do not rely on the resource file, add RESOURCE=OFF to the CONFIG.FPW
(2) Mark FOXUSER.DBF and FOXUSER.FPT as read-only. They can be shared, but user setting changes normally stored there will not be saved.
(3) Assign a separate FOXUSER file to each machine.