i looked into doing this recently when copying files for an upgrade from a CD.... and to tell the truth i could not find a way to change the attribute in VFP. what i ended up doing is creating a small COM object written in VB which can easily do this:
SetAttr filename, vbNormal

where filename is the file you are changing the attribute of (obviously)

just call the object procedure whenever you need to change the attribute.
but as far as i could work out, there was no function i VFP that allowed you to change the attribute. you can view the flag... but that is not very helpful at all.

Jordan :)