Normally this problem comes if you have pirated copy of the game or if someone has made a pirated copy of your game code which is given to you when you by the game. What you can do is you can try reinstalling the game. Before that first uninstall the game, than cleanup your computer using disk cleanup utility which comes with the Windows Xp. After cleanup try to install the game and install full game with custom option no express or typical option. I hope this could solve your problem.

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