Well, you would have to start by subclassing the ProjectHook class that comes with VFP 6. Then, in the Init method, add the code to set the active project's DebugInfo property to .F.
Finally, associate this project hook to attach itself to any new projects with the Tools->Options dialog, Project page.

This is the short description, obviously. Also, there's a LOT more that you can do with a ProjectHook and the Project object.

>>The only way of which I'm aware is to use a Project Hook and set the property in the Init method. Currently, there is no global option to set, unless someone knows an undocumented feature that I don't know about. :)
>
>Not sure, I understand, what should I do. Could you please explain for dummers a little more?