What is an authentication key if you dont have one

It's a unique series of numbers/letters found inside a video game case/manual for activating the full game features.

If you don't have one you can't activate the game.
You'll probably have to get another copy. I know a website,you could have a try,i have bought cdk from them,they are realible and have excellet service
url:www.guy4game.com?aid=770
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