Just installed scratch with xfce4 on an oldish machine, downloading all the needed packages through my wifi adapter.
On first boot wifi is down, and there is no application I can use to choose and connect to my wifi access point. I realize that xfce's own Airconfig has never lifted off and is currently unreleased, abandoned and unmaintained, so xfce users usually use NetworkManager or Wicd. I would suggest that any of these is installed by default when xfce is chosen during installation.
