BOAC,
Most software firewalls will alert you to in and outbound traffic, and will give you the option of blocking it. I've been using
ZoneAlarm for a while, but there are others such as Norton Personal Firewall. I would think that your virus program would warn you if it had been tampered with, but if not you should be able to boot from the emergency CD or floppies and scan the computer that way.
goates