There are many considerations and parameters for creating a customized implementation using an answer file. For example, if your organization does not have a volume licensing solution for Windows XP Professional, you'll need to consider Windows Product Activation (WPA), which requires that each unique installation have a unique product key. In this case, you need to create a separate answer file that includes the unique Product Key for each computer on which Windows XP Professional is installed. Refer to the Microsoft Windows XP Professional Resource Kit Documentation for more details about modifying the answer file for automated installations.
But I will take you word for it.
Thanks again
Daren