// глобальные переменные
var
  PIDNeeded:Cardinal;
  Handle1: string;
 
function EnumWindowsProc(Wnd:HWnd):Bool;stdcall;
 var Text:string;
     TextLen:Integer;
     WndPID:Cardinal;
  begin
   Result:=True;
 
   if not IsWindowVisible(Wnd) then
      Exit;
 
   GetWindowThreadProcessID(Wnd,@WndPID);
 
   if WndPID=PIDNeeded then
    begin
     TextLen:=GetWindowTextLength(Wnd);
     SetLength(Text,TextLen);
 
     if TextLen>0 then
      GetWindowText(Wnd,PChar(Text),TextLen+1);
 
     Handle1:=Handle1 + ' ' + text;
    end;
  end;
 
 
 
 
procedure TMSServisPK.FillWindowList(PID:Cardinal);
begin
  if PID=0 then
    Exit;
  PIDNeeded:=PID;
  EnumWindows(@EnumWindowsProc,0);
end;

.....
Handle1:='';
MSServisPK.FillWindowList(Cardinal(FEventResult1.TargetInstance.ProcessId));
....
MyQuery1.ParamByName('pHandle').Value := Trim(VarToStr(Handle1));