Hello, this game comes highly recommended, but before I install it, I figure I'd be belt and suspenders sure that my meager laptop will actually be able to run it.  I've got an Intel Core 2 Duo P9500 CPU running at 2.53 GHz, an Intel GMA 4500, 3GB of RAM, and a 1280x800 display. 

While I'm here, I've never downloaded a game before, (heck, before this year I think the last game I purchased was Alpha Centauri, many years ago) is there a recommended place from which to download, and if in the inevitable future (next year, probably) when I buy a new laptop, how would transferring a downloaded install work?  I'm a dinosaur and am totally unfamiliar with the concept of how games work when you don't have their disk.

Thanks!