Hola, para Xp hacelo asi:
Código Delphi
[-]
ShowWindow( Application.Handle, SW_HIDE );
SetWindowLong( Application.Handle, GWL_EXSTYLE,
GetWindowLong(Application.Handle, GWL_EXSTYLE) or
WS_EX_TOOLWINDOW and not WS_EX_APPWINDOW);
ShowWindow( Application.Handle, SW_SHOW );
y para mostrarla:
Código Delphi
[-]ShowWindow( Application.Hanlde, SW_SHOW );
Bytes...