Abstract: A system and method for retrieving and assigning a unique media access control (MAC) address to a network adapter card in a computer system that uses the network adapter card to connect to a data network. The computer system includes a communications application for invoking a network connection to a remote server. The remote server includes a MAC address list that stores MAC addresses that have been assigned to network adapter cards according to serial numbers. The remote server includes a web page that requests the user to enter a serial number. The remote server uses the serial number to search for a MAC address in the MAC address list. When the remote server finds the serial number, it stores the corresponding MAC address in a file and sends the file name to the user. The user then requests the remote server to download the file by file name, or by FTP URL. The computer system receives the file and an update program reads the MAC address from the file and sends the MAC address to the network adapter card.