Gamespy Rome total war Online why cant i play?

Ok I am on wireless internet an di cant play i bought the game so i installed game spy and i remember playing online before but now it wont let me so i entered my gamespy name and it said invalid cd key but ont he inside of the cd case with disc 1 and disc 2 it said this

24 digit code i dont know where to enter that code.

That code is the CD key for installation. Chances are your computer is having an issue with connecting to Gamespy. You might want to consider troubleshooting your network, or actually assessing the issue automatically when you are prompted to do so. I don't use the system because I think it's evil, but I've had similar cross-network issues with Blizzard's Battlenet. Good Luck!