Instructions
Insert the "Need for Speed: Underground" CD into your CD drive. Wait for the installation process to start automatically.
Click "Install."
Enter your serial code, which is located in a white box at the bottom left corner on the back of the "Need for Speed: Underground" CD case.
Click the "Next" button once you've entered your serial code.
Click the "Next" button again on the screen that appears after the serial code screen.
Click either "Register Now" or "Register Later." Choosing "Register Now" will send you to the "Need for Speed: Underground" registration website.
Wait for the installation to finish after indicating that you want to register. "Need for Speed: Underground" will start automatically once installation completes.