I think this feature was introduced with Vista: in the Explorer, when you shift to file renaming, the entire filename is selected by default, except the extension. This is surely a friendly feature to ensure you don't change the extension by mistake. I don't like this friendly feature. I want the whole file name selected, with extension, by default. It's there a way to do that?
Note: I'm not asking how to make extensions show. This issue appears even with extensions displayed.