According to windows API documentation, a window with style WS_EX_TOOLWINDOW does not show up in taskbar. I created a window with WS_EX_TOOLWINDOW, sure enough, it doesn't show up in taskbar. Now if I remove the WS_EX_TOOLWINDOW style, it shows up in taskbar, so far so good. But if I add the style again, it still stays in taskbar.
It seems that once it lost WS_EX_TOOLWINDOW, it always stays in taskbar, even if you put the style back in.
Has anyone run into this problem ? Other than destroying and recreating the window, how do you fix it ?