Pull the power cord and the ethernet cable from the back of the modem and wait 30 seconds.
After 30 seconds, plug back in the ethernet cable and power cord.
Wait for the modem to go through its startup procedure.
If you have a wireless router, unplug your router's power cord and ethernet cable and wait 30 seconds.
Be sure to connect the modem first and wait for it to finish the startup procedure.
Plug the ethernet cable back into the router. Be sure to plug it in to the WAN, or Internet, port.
Plug the power cord back into the router.
Restart your computer and try to connect to the internet.