>You could use a third party data encryption tool, where you put the unlock key in your app. I haven't had the chance to try one yet, but would appreciate any comment on the issue.

Encryption will stop the (ab)users from being able to _understand_ the data, but not from maliciously destroying the files.


>>>Is there a way to prevent access to the users to the DBF files outside a VFP application, lets say to keep them from opening them thru VFP developement or erase, rename or copy them thru the Windows Explorer.
>>>
>>>All the files are in a Windows NT server, I suppose that there could be a hidden propery to the files or something like that.

Hidden property won't work. You can tell explorer to show hidden files. NT 5.0 is supposed to have far better security than 4.0.