Thanks for the help, but I'm no where nearer sorting it out.
It didn't come with any driver disc and I don't see a name on it. I bought it off ebay for a couple of quid. And a network adapter is found when booted up, but I can't install without knowing its manugacturer.
There's a serial number: 0010A709C45B ND012C 110
On the chip (RMC) it says: RTL8139C 0C211Q1 108B Taiwan.