Can anybody tell me what a USB Network Adapter does? I'm wanting to network 2 PCs (wired connection since they are both on the same desk!)so that they share my BTBroadband service. The older of the two doesn't have an ethernet port or a network card. There's no room on the motherboard to install a PCI card. Would the Adapter provide an alternative or does it have a different role?
You are barking up the wrong tree. A USB adapter (though it's actually a receiver, so I don't think that they should be described as adapters) is intended to be a cheap and simple way of receiving a wireless signal. It has nothing at all to do with Ethernet networks.