Andy -

The FoxUser.dbf and FoxUser.fpt are created when the user first launches
VFP or a VFP app. I have noticed software on some users systems that automatically creates desktop icons when new programs are launched. I think it was shareware but can't recall.

If the machine does not have VFP or some other software that registers a .dbf file type - or if they have the default Windows file icon selected for a .dbf file type in their Explorer you would see the icon you described.

So, it may not be anything you are doing or failing to do.