When you first run Galactic Civilizations, you enter your serial number and it gets registered to you.
It sounds like you bought a used copy -- this means it was already registered to someone else,
and you'll need to either 1) get the information about the account from the original registerer
(I think this will be their Impulse ID and password; essentially they'd be giving their account to you),
or since that's pretty darned unlikely, 2) contact Post-it-games and get a refund. I'm sure they
will be willing to assist you to maintain their 5/5 rating. Perhaps they didn't realize that only
one person at a time could use Galactic Civilizations.
Once you get a 'real' copy, one of the joys of Impulse is that you can have the software installed
on several machines, as long as you're only logged in to one at a time (think laptop and desktop,
for instance).
