Step 1: Turn the modem off and then back on again.
Turn off your modem using the power switch on the back, wait 15 seconds, and then turn it back on. After waiting 45 seconds to allow the modem to synchronize with the server, try reconnecting to the Internet.
Step 2: Verify that all lines and filters are properly connected.
Verify that a loose cable or a missed filter isn't affecting your Internet connection.
Step 3: Verify that your Network Interface Card (NIC) is working correctly.
Make sure the cable between your modem and your computer's Network Interface Card is connected and the green light is on.
Step 4: Remove and reconnect all network computers.
Try to isolate the connection problem by removing all the networked computers and then re-connecting them.