procedure TForm1.Button1Click(Sender: T);
var
   PIDL:PItemIDList;
   Info:TShellExecuteInfo;
   pInfo:PShellExecuteInfo;
   WaitCode:DWord;
begin
 {get PIDL of the virtual folder}
   SHGetSpecialFolderLocation(Handle,
                              CSIDL_PRINTERS,
                              PIDL);
   {Pointer to Info}
   pInfo:=@Info;
   {Fill info}
 with Info do
 begin
    cbSize:=SizeOf(Info);
    fMask:=SEE_MASK_NOCLOSEPROCESS+
           SEE_MASK_IDLIST;
    wnd:=Handle;
    lpVerb:=nil;
    lpFile:=nil;
    {Executable parameters}
    lpParameters:=nil;
    lpDirectory:=nil;
    nShow:=SW_ShowNormal;
    hInstApp:=0;
    lpIDList:=PIDL;
   end;
   {Execute}
   ShellExecuteEx(pInfo);
   {Wait to finish}
 repeat
    WaitCode := WaitForSingle(Info.hProcess,500);
    Application.ProcessMessages;
   until (WaitCode <> WAIT_TIMEOUT);
end;

Speed test