This article demonstrates how to hide all icons on the desktop.
var
DesktopWnd : HWND;
procedure TForm1.Button1Click(Sender: TObject);
begin
DesktopWnd := FindWindow('Progman', 'Program Manager');
if DesktopWnd > 0 then begin
DesktopWnd := FindWindowEx(DesktopWnd, 0, 'SHELLDLL_DefView', nil);
if DesktopWnd > 0 then
DesktopWnd := FindWindowEx(DesktopWnd, 0, 'SysListView32', nil);
end;
if DesktopWnd = 0 then
ShowMessage('Error - could not find desktop')
else
ShowWindow(DesktopWnd, SW_HIDE);
end;