1, check the account password is input error, pay attention to the decimal point or space.
2, check the network card driver is normal.
3, to see if the network cable is connected successfully. (View "Local Area Connection").
4, to see if the broadband is overdue or due.
5, the first four have tried if still not, the computer and the light cat off together. Wait until 5-10 to reconnect again. It may be that your broadband is off the normal line, and the broadband service provider thinks you're online. You'll get "error 629" or "Error 691" When you're up there.
6, if the front is not a problem, it should be the broadband remote end is interrupted. Call the broadband service provider and see if they have closed the port.