How to crack the time bound demo computer PC games ?

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I was playing a game called Star defenders 3.0 demo. In all these demo games, it typically allows us to play for one hour ( 60 minutes) only. Even when I close the game, and restart it, I am allowed to play only for the remaining time. It asks for an email id and a code, to continue playing after 60 minutes... and for that I have to pay $20 or so, to purchase the full version of the game. Are there any ways to get over this hindrance ? Please be specific, as I am not very computer savvy, I am a beginner, but inclined to learn fast. Thank you very much, my dear friends, and fellow mylot netizens for helping me. yours friendly Heartwalker