In the last couple of days, AVG have issued a major program upgrade - maybe they fixed it for you? Worth getting the latest upgrade to see. You will need to disable AVG and just use the control panel to check for upgrades, or maybe even download a complete reinstall pack. Dont go online without SOME anti-virus though....
You could do worse than try the German-based AntiVir personal. It works fine, but lacks the sophisticated virus updating prodedure. (AVG has even restarts of interrupted downloads at the point of break - remarkable for a free AV)