回複：DSL. WINDOWS VISTA 謝謝！！！！

* The modem is turned on.
* The Ethernet cable is plugged correctly into the Ethernet port on the modem and on your computer.
* The phone line is plugged correctly into the modem and the phone jack.
* You are not using a DSL filter between the phone jack and the modem.
* Now check the lights on your modem. This can show you where is the problem- is it the Ethernet connection, the power to the modem, or the cable connection?
* Turn off your modem and then the computer. Wait for 20 seconds and then put it back on.
* Again turn off your router, wait for 10 seconds and then turn back on.
* Connection problems can occur due to Winsock corruption. To work around in this case open Network Diagnostics.

* Open Network Diagnostics by right-clicking the network icon in the notification area, and then clicking Diagnose and repair. For detailed explanation on : How to determine and recover from Winsock2 corruption click here