There may be occasions when you need to reset your cable modem/router to factory defaults, for example if you have changed the Username and Password and lost the new values. Note that if you reset your device to its factory defaults, you will lose any changes you have made to settings in the device.
You should backup your settings before you do this. Instructions HERE
FACTORY RESET (or "HARD RESET"):
1. Make sure the power to your unit is ON
2. Disconnect the Coaxial cable in the back of your modem
3. Use a straightened paperclip, tip of a ballpoint pen, or push pin
In the back of your unit is a RESET hole
4. Locate the RESET hole, located in the back of your device.
5. Push the RESET hole in for 25 seconds, then let go
6. Wait for the unit to reboot, and reconnect. You will see the lights starting to come back up on the front of the unit
If you saved a copy of your settings configuration, load your backup configuration file now.