No yellow bios is on.
Anything else?
If it is the port on the motherboard can I just install a ethernet card?
yes, should be no problem to do so.......
I had a MB once that had 2 onboard LanPorts..... one took a hit when lightning ran in and took out my cable modem, router, microwave, and living room cable box & TV..... I switched over to the other onboard port and it worked fine...but ended up installing an add on PCI network card to be safe, until I had a chance to replace that MB all together....
that MB is still in use , built a pc 4 yrs ago and gave it to oneof my neices, got lucky with it only taking out the one Lan port....
( sorry for rambling )
anyhows.. it is possible that you grounded it out accidently without knowing so maybe......
did you check your control panel / system / hardware / device manager / network adapters / (named adapter ) to see if it had any problems? ( <--- path is if u eunning winXP )