in get_state(), run:

if not state.get(u'quarantined'):
  top = platforms.win.list_top_windows()
  if top:
    state[u'quarantined'] = 'Found top level windows: %s' % ','.join(top))

This is fairly simple. The challenge is that there are currently 91 bots with a top level Window, 48 with a u'ConsoleWindowClass' (the Swarming bot). We need to knock down most of the sources of top level windows, so that we don't loose most of the Windows fleet all at once.