Code:

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;