When you create a menu bar, a funny line appears underneath (for XP and Win7 at least). How can I get rid of this line? I know that some applications, such as Firefox and Thunderbird, have done so.
Here’s an illustration:

I am programming in C, using the Windows API. My menu is loaded from a resource file.
I’d say that line is supposed to be there (Run a simple application like calc and see) If you look at an application like Explorer (Or IE4-6) in XP, its menu is actually a toolbar inside of a rebar.
If you look at a function like GetMenuBarInfo() you will see there is no border property you can query or set.
If a 1 pixel line is that important, you probably have to A) Do some owner drawing on the menu to paint over that line or B) Implement a custom menu control (MS even has a tutorial for IE/Explorer style menus)