Won't update software; says I'm not connected but I am

Get the followig message when I try to update the virus software - “Failed to update the virus signature database. Please check your internet connection and try again later.” I’ve checked the connection and it’s working perfectly. Can someone tell me how to fix this? Bought this computer from someone who already had Comodo installed. Can’t figure out why I’m having this problem.

Welcome Padmaananda. Check under More, Preferences, Update and make sure the next line is present and ticked.
http://download.comodo.com/
If not add it and tick it. Hope this helps. Kind regards.
Edit- also if not using proxy make sure it is not ticked under More, Preferences, Connection.

Does the problem still occur or was it just a temporary glitch?