::CommandBar_Show(m_pWndEmptyCB->m_hWnd, FALSE ); using VS2005?

I am not certain if this will be helpful however according to http://msdn.microsoft.com/en-us/library/ew94tebd.aspx m_pWndEmptyCB is no longer supported because you now control the creation of the command bar so somewhere in your code you would have a call to CommandBar_Create http://msdn.microsoft.com/en-us/library/ms908131.aspx which will return the handle to your command bar when called (if successful), you could store this handle in a member variable, e.g.:

// Declare handle to control bar as object member variable
HWND hCmdBar;

// Initialize when creating the command bar
hCmdBar = ::CommandBar_Create(...

and later on pass it as the first argument to the CommandBar_Show method, e.g.:

::CommandBar_Show(hCmdBar, FALSE );

Do you use MFC in your project?
I think Lordof Ports is right. IN my application I just don't create the command bar, but the main window has WS_POPUP style, so it can cover the whole screen. I don't use the MFC.

One more thing - I control the WM_ACTIVATE to hide the system controls.
for example, this code will find the task bar:
HWND hWnd = ::FindWindow(TEXT("HHTaskBar"), NULL);
then: ShowWindow(hWnd, SW_HIDE);

or SIP button:
HWND HWnd = ::FindWindow(TEXT("MS_SIPBUTTON"), NULL);

Yes I use MFC in my project.

I also control the WM_ACTIVATE and I 'had' the following:
void CAbout::OnActivate(UINT nState, CWnd* pWndOther, BOOL bMinimized)
{
          CDialog::OnActivate(nState, pWndOther, bMinimized);  
          SHFullScreen( m_hWnd, SHFS_HIDESTARTICON|SHFS_HIDETASKBAR|SHFS_HIDESIPBUTTON );
          MoveWindow(0,0,240,320,TRUE);
          ::CommandBar_Show(m_pWndEmptyCB->m_hWnd, FALSE );      
}

I will try out your suggestions above to replace the m_pWndEmptyCB.
Thanks

The following does not hide the bottom SIP:

HWND HWnd = ::FindWindow(TEXT("MS_SIPBUTTON"), NULL);
::ShowWindow(HWnd, SW_HIDE);

Any ideas??

Thanks

Check if HWnd is NULL perhaps. According the FindWindow's description http://msdn.microsoft.com/en-us/library/ms633499.aspx it does not search for child windows, use FindWindowEx http://msdn.microsoft.com/en-us/library/ms633500(VS.85).aspx to search for child windows.

The post at http://forum.soft32.com/pda/Removing-SIP-icon-Command-Bar-ftopict58785.html might also be helpful although in that solution the button is moved.

Probably I understood what happens - after these games with the commandbar you need to redraw your window also - call invalidate for the main app window