1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:

procedure ListFileDir(Path: string; FileList: TStrings);
var
  SR: TSearchRec;
begin
  if FindFirst(Path + '*.*', faAnyFile, SR) = 0 then
  begin
    repeat
      if (SR.Attr <> faDirectory) then
      begin
        FileList.Add(SR.Name);
      end;
    until FindNext(SR) <> 0;
    FindClose(SR);
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  ListFileDir('C:\WINDOWS\', ListBox1.Items);
end;