If you registered it at release, you should already have it registered here (as Impulse was ours at the time), as well as access to the Fallen Enchantress beta. If it doesn't already show up at the URL Doc posted above, support can help you locate your old account.

Thanks for the help guys, I'm going to try to find a solution on my own. StarDock support told me that they don't offer support for serial keys lost or possibly registered previously.

Sadly, without some kind of proof that the game was purchased (receipt, serial, registered email, etc) it becomes impossible to know who really lost their serial or who is trying to scam us.

Thankfully, as we have stopped selling in retail the chain of purchase to player is easier to track.

Sorry about that.