Ethernet Controller Drivers Not Installed under Devices

GX270 desktop (bought 2004) with onboard network adapter (Intel PRO/1000 MT) that quit working but I installed a Realtek card. I had this card working with Red Hat and even a beta version of Vista. I've since reverted back to my Dell XP version using Dell CD but can not get an IP from my dhcp host/router. After the XP install, the Realtek RTL8139/810x NIC shows to be properly working under Devices however I have Four "Other devices" with the yellow question mark. They are Ethernet controller, Multimedia Audio Controller, SM Bus Controller and Video Controller (VGA compatible). Two other reinstalls & formats produced the same result. I've tried Reinstall Driver from Ethernet Controller properties but no luck finding a driver. I'm wondering if the Dell OEM XP install only knows what to do if the onboard Intel network adapter is working. Does anyone have any ideas? Thanks!