Les raisons for the internet light to be off are quite easy to find.
In 90% of all cases the modem was reset to factory default, either through a firmware upgrade, or because (more often) someone in the household held the "Reset" button a little too long.
If you know that you have reset the modem to its factory default (by pressing the reset button), we recommend you went to our "Download" section under the "Support" tab to download the configuration guide for your modem (if the modem is yours and is not listed in the "Download" section, you may need to contact the manufacturer for assistance).
If you are certain that you have not reset the modem to its factory default, we recommend you gave us a call for further diagnostics.