I have a windowed app on Windows 7. I double click the title bar to make the window max the entire screen. The taskbar remains visible on the bottom, but this is undesired. I did some research, and this is what I came up with. However, the task bar is still showing. Any thoughts would be helpful. Thanks.

Edit: To clarify, this is for a fullscreen-windowed game that covers the taskbar, and not actually trying to kill the user's taskbar.

                    ShowWindow(g_hWnd, SW_HIDE);

                    LONG lStyle = GetWindowLong(g_hWnd, GWL_STYLE);
                    lStyle &= ~(WS_CAPTION | WS_THICKFRAME | WS_MINIMIZE | WS_SYSMENU);  
                    SetWindowLong(g_hWnd, GWL_STYLE, lStyle);
                    
                    LONG lExStyle = GetWindowLong(g_hWnd, GWL_EXSTYLE);
                    lExStyle &= WS_EX_APPWINDOW | WS_EX_TOPMOST;
                    SetWindowLong(g_hWnd, GWL_EXSTYLE, lExStyle);
   
                    SetWindowPos(g_hWnd, HWND_TOPMOST, 0,0,0,0, SWP_FRAMECHANGED | SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER | SWP_NOOWNERZORDER);
                    ShowWindow(g_hWnd, SW_SHOW);

Thanks, but even removing the two flags still show the taskbar, and oddly enough the task bar is somewhat cut off near the top.

Well, if you played Angry Birds on the Mac, a full screen game is actually a window. It covers the taskbar on the bottom. I'm trying the same for Windows.

I did auto-hide the taskbar, and the window dimensions were long enough.

So, I'm not trying to get rid of the taskbar, but trying to do a fullscreen-window feature that will cover the taskbar.

So far, the window is only partially above the top of the taskbar.

Yes. The issue is OpenGL won't render as a single buffer in fullscreen mode due to Aero, I believe. It does work when it's in windowed mode. So If I double click the title bar (or send a message to call WM_SIZE), I can get single buffering working as if it's full screen for the project's needs. If I auto-hide the taskbar, the window's dimensions cover the entire monitor, and the single buffer works. So, now I'm trying to cover the entire taskbar with the window when it's not in auto-hide.

Someone suggested just making and drawing to an FBO (frame buffer object) and send that buffer to the back buffer, which gives the same feel as a single buffer. I haven't studied that far into OpenGL, so perhaps this is a better solution down the road than black magic with window manipulation. I was just thinking short-term with a window reaching the monitor's dimensions, but I can always just auto-hide the taskbar as I study until that point. Thanks for the idea on auto-hiding the taskbar as I study.

Edit: This ended up covering the taskbar for a full-screen window effect with single buffering, despite Aero, though I don't recommend it for real projects:

        LONG lStyle = GetWindowLong(win_getHandle(), GWL_STYLE);
            lStyle &= ~(WS_CAPTION | WS_THICKFRAME | WS_MINIMIZE | WS_SYSMENU);  
            SetWindowLong(win_getHandle(), GWL_STYLE, lStyle);
                       
            SetWindowPos(win_getHandle(), 0, 0, 0,     win.SystemInfo.DesktopResolution.right-1,     
                win.SystemInfo.DesktopResolution.bottom-1, SWP_SHOWWINDOW);
            MoveWindow(win_getHandle(), 0, 0, win.SystemInfo.DesktopResolution.right+1,
                win.SystemInfo.DesktopResolution.bottom+1, TRUE);