function AkivierenActiveDesktop(activate: boolean): Boolean;
const
  CLSID_AD: TGUID = '{75048700-EF1F-11D0-9888-006097DEACF9}';
var
  hObject: IUnknown;
  AD: IActiveDesktop;
  ComponentsOpt: TComponentsOpt;
begin
  hObject := CreateComObject(CLSID_AD);
  AD := hObject as IActiveDesktop;
  try
    ComponentsOpt.dwSize:=SizeOf(ComponentsOpt);
    AD.GetDesktopItemOptions(ComponentsOpt,0);
    ComponentsOpt.fActiveDesktop:=activate;
    AD.SetDesktopItemOptions(ComponentsOpt,0);
    AD.ApplyChanges(AD_APPLY_ALL or AD_APPLY_FORCE);
  finally
  end;
end;