Greetings,
Not good if you have verified it's enabled in BIOS.
Is there a Network Adapters heading in DM at all?
Other option, load set up defaults in BIOS, save, restart.
CLR_CMOS, Load set up defaults, restart
Pull MB battery, wait a few minutes, retest
You can try to rescan for hardware changes in Device Manager, but you could be looking at RMA if all BIOS settings are correct and windows doesn't see the device at all.