I hate that, people who buy something, use it and return it and then seem proud.
But COSTCO!! YAY!! That's one of the few things I really miss about the states.
Both chips are fine, the Turion X2 and the Core Duo. You probably won't notice much difference.
The Chips use simialir amounts of power. The Turion x2 uses AMDs new socket for mobile chips so will probably be upgradeable in the future....
It probably doesnt have the correct drivers. Or the vista ones dont work. Try it on your laptop, it appears newer so therfore should work.
Vista should have generic drivers for most cases.
The go with 128 will game way better than the one with 64, 64 meg is too low nowadays. I'd be surprised if this fred got locked, it's normally only where alienware supporters trash dell or vise versa and hammerhead gets stuck in that...