Intel Pro/100 VE not recognized

I have upgraded to ZEN 7.01 HP2 to solve some problems with newer hardware and that has worked fine. Now I find that I have some older desktops (Dell OptiPlex with Intel Pro/100 VE network cards) that will no longer work. We use PXE boot and it will no longer recognize this card. How can I get the upgrade to ZEN to work with this older NIC? Thanks form any help.