I've found boards that don't show up until I install the Intel Chipset driver package. There could be other reasons but having bumped into this too many times along with issues with XP (you didn't write XP SP3) I think what you are seeing has been seen too many times.
Bob
Just installed a new Intel Pro/1000 GT Desktop Adapter in PCI slot of Dell Optiplex 780 running Windows XP Professional 32 Bit. No matter which PCI slot I put adapter the device manager does not show it. Checked Dell Bios A08 and PCI is enabled. Computer is currently running off its NIC for internet. But, I need this adapter to connect to another local network. Tried checking hidden devices on device manager but that did not show it either. Please Help!

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