So this is happening on my parents' PC, Dell Optiplex with a Broadcom NetLink Gigabit Ethernet adapter. I plug in the Ethernet cable directly to the Modem to make sure no other factors may be influencing the situation other than the Adapter it's self, and nothing. No Port num flashing on the Modem, no light flashing on the Ethernet port on the Mobo. However when i disable the device and then unable it again, or uninstall the driver and install it again the lights do start flashing but the Ethernet cable still isn't being detected. I have tried a different cable as well, same story.
I have thrown in a PCI Ethernet card i had in my legacy hardware box, and that's working fine. And the other thing is the device isn't reporting any error codes, says it's working properly in Device manager.