Installing GCII on a new Vista machine; my old XP laptop is fried?

My computer is toast. Graphics card fried, motherboard... It was a Dell and they don't supply the spec. anymore. Well, you get the message. The machine had my only copy of GCII on it. Fortunately my email's all in Exchange elsewhere on the net, so I haven't lost my GCII serial numbers. They're somewhere. To add to the trickiness of the problem the old machine is XP and a new one would have to be Vista (gnash, gnash).

Is it possible to reinstall on the as-yet theoretical new laptop using the old serial numbers. If so, how? I've had a search through the forums about this but maybe I haven't been looking hard enough? Maybe in it's in the manual? The manual is toast...