uses
  ComObj, ShlObj, ActiveX; 
 
procedure EnableActiveDesktop(bValue: Boolean); 
const
  CLSID_ActiveDesktop: TGUID = (D1: $75048700; D2: $EF1F; D3: $11D0; 
    D4: ($98, $88, $00, $60, $97, $DE, $AC, $F9)); 
var
  MyObject: IUnknown; 
  ActiveDesk: IActiveDesktop; 
  twpoComponentOpt: TComponentsOpt; 
begin
  MyObject := CreateComObject(CLSID_ActiveDesktop); 
  ActiveDesk := MyObject as IActiveDesktop; 
  with twpoComponentOpt do
  begin
    ZeroMemory(@twpoComponentOpt, SizeOf(TComponentsOpt)); 
    dwSize := SizeOf(twpoComponentOpt); 
    fEnableComponents := bValue; 
    // fActiveDesktop := True; 
  end; 
  ActiveDesk.SetDesktopItemOptions(twpoComponentOpt, 0); 
  ActiveDesk.ApplyChanges(AD_APPLY_ALL); 
end;