To understand the necessity of the "No CD" crack, one must understand the context of late-2000s PC gaming. FIFA 08 was released in an era where physical media was the primary distribution method. To prevent unauthorized copying, EA utilized DRM solutions—most notably SafeDisc or SecuROM—which required the user to insert the physical game disc into the optical drive every time they wished to play.
You may need to install "DirectX End-User Runtimes (June 2010)" to provide the legacy files the game requires. fifa 08 no cd portable