Has your network pci card has been installed correctly in a PCI Slot that is not shared with any other hardware. Was recognized by windows as new found hardware when you rebooted system ?
Pci card may show up in device manager as a ok if all is well with the fitting and winxp has selected its own drivers for it.
What will not be reported with a PCI network card is any conflict or sharing with other poss hardware. Sharing with a Host controller likes of via or promise would not matter as this is basicly software.
To check open up Systems information tool click on the + by hardware then click on IRQ'S