Why are you PMing random people for help with this? Seriously, have you no manners? I have never posted in the Sins forums, so how do you even know that I own the game or can help you with your issue? Email support@stardock.com for cd-key-related problems. Or, you know, you could do this:
Under your start menu, Programs > Stardock Games > Sins of A Solar Empire > Sins Launcher. Then click on the button for serial number. That should be your CD key. (At least, that's what I used.)
That is from a thread (http://forums.impulsedriven.com/361403) only a few lines below this one. Ugh.
I hope that you haven't PMed too many other users with your "plz help" nonsense. You didn't even allude to your problem, so I had to track down your post to figure out why I was getting these spam messages. Honestly, what inspired you to send TWO generic "plz help" messages to my inbox within 15 minutes? I am astounded.