uses

   ComObj, ShlObj, ActiveX;

 

 procedure EnableActiveDesktop(bValue: Boolean);

 const

   CLSID_ActiveDesktop: TGUID = (D1: 048700; D2: $EF1F; D3: D0;

     D4: (, , {text}, , , $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;