A system uses a protocol stack on a card external to a motherboard in a target computer system. A processor on the motherboard is able to make use of the external protocol stack during boot-up of the computer, or at any other time, so that it is not necessary to load the protocol stack into the motherboard's memory. This saves time, memory, and disk space and permits an external, managing, computer system to communicate with a computer just after power-up without loading and configuring a protocol stack so that the managing computer system can control the boot-up of the target computer system. The extra memory saved, especially, is important in running many MS-DOS applications, such as firmware flash utilities. A preferred embodiment of the invention uses a UDP/Internet Protocol (UDP/IP) stack resident in a Preboot Execution Environment (PXE) on, e.g, a network card. The approach described herein can be applied to other utilities, protocol stacks or resources (hardware and software) on other cards.