I had the same problem with quoted driver on Toshiba 64bit upgrade. Stopped working after few days. Reinstalled OS to solve problem.
Green light shows hardware OK.
Check Windows updates installed and see if Realtek driver update was installed. This has caused problems to others.
Time for you to contact Toshiba.
Personally gone back to windows 7 as windows 8, for me, was a mistake.
Edited by flippery (Mon 15-Apr-13 20:16:48)