>does anybody know how to prevent users from openning VFP tables. Some of my users have a VFP installed on their PC and they can access all VFP free tables in my data folder. Do you know any effective way how to stop it?

Two ideas would be to change the name and extension of the tables, kindof trick them, or in code, corrupt the table at a low level intentionally when you close a table down, and un corrupt it when before you use it.