Hmn, it musnt be a warez version.
Some players i know having a original version have same problem.
Think sometimes gp4setup installs the game but dont write correct registry. I had same problem. Ever i loaded cd autostart tells me to install the game. But it was allready installed.
Use gp4 registry editor to set your gp4 loaction or reinstall the whole game.
Have a look to your registry and search for gp4.exe. There's n entry but nothing about gp4 loaction. This error is on winxp /2k only.
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