Solution:

It could be the PCI IRQ assignment problem. The network card may only be reconized in some IRQ channel. A possible way is to change the PnP setting in CMOS. You may make it to "manual" or "auto" and try assign some IRQ channel to ISA and PCI. This will make the PnP IRQ configuration change. Try it in DOS and see the configuration table under the boot up window. If it detacts fine in DOS, then try Windows system.