function MyRemoveDir(sDir : string) : Boolean;
var
  iIndex: Integer;
  SearchRec: TSearchRec;
  sFileName: string;
begin
  Result := False;
  sDir := sDir + '\*.*';
  iIndex := FindFirst(sDir, faAnyFile, SearchRec);

  while iIndex = 0 do
  begin
    sFileName := ExtractFileDir(sDir)+'\'+SearchRec.name;
    if SearchRec.Attr = faDirectory then
    begin
      if (SearchRec.name <> '' ) and (SearchRec.name <> '.') and
      (SearchRec.name <> '..') then
        MyRemoveDir(sFileName);
    end
    else
    begin
      if SearchRec.Attr <> faArchive then
        FileSetAttr(sFileName, faArchive);
      if not DeleteFile(sFileName) then
        ShowMessage('Could NOT delete ' + sFileName);
    end;
    iIndex := FindNext(SearchRec);
  end;

  FindClose(SearchRec);
  RemoveDir(ExtractFileDir(sDir));
  Result := True;
end;

// ***************************** //
//           Пример:             //
// ***************************** //
if not MyRemoveDir('D:\myDir') then
  ShowMessage('Can NOT delete dir');

// Кстати, системные, скрытые и
// read-only файлы тоже будут удалены.