Even if TCP/IP isn't the problem, it's not going to hurt anything by uninstalling and reinstalling it. The winsock reset is a good tool also. Sometimes the TCP/IP stack gets corrupted, especially from viruses and spyware. If these two things that uid=[0] suggested don't work, I'm thinking it's the card, the cable, or the port. Once you find your Windows installation disc, you may also want to try Start>run> sfc /scannow
You will be prompted for the original installation cd. This restores many original system files, which could have become corrupt after virus removal.