Well, that's weird, because those have to do with the window style.
You'll have to make sure the window style is correct...
I believe you need the WS_SYSMENU style to see the max/min buttons.
And as you know, reinterpret_cast and static_cast are C++ only, so you have to do a C-style cast to make it C.
But what's weird is that I never get the warning you do by casting int to HMENU, even with a C-style cast.