please help please!!required file not found

i have nba live 08 for my PC and as of lately what will happen is this.....i double click on my nba live 08 icon on the desktop my nba live will start up i will see the disclaimer, EA sports intro,and right before the main menu comes out it will minimize itself and i get a message "required file not found please insert nba live 08 cd" and yes i do have a fully purchased version of nba live 08 i have the cd itself and everytthing so dont think i dont because i dont respect bootlegging! please if anyone can help me or point me to the right direction to fix this issue it would be appreciated

When all else fails, reinstall.