Message - there is a problem with this site's security certificate

Hello Graham.
Thank you for contacting us. We would like to inform you that the issue is not with AVG but it is with the date and time settings of your PC. Many website security certificate problems can be fixed by making sure your computer’s clock has the right time, day and year. At times the clock can get out of sync and make your web browser think the certificate isn’t valid. Thank you.

It may be coincidence, but since we had a power failure yesterday, each time I attempt to visit any internet website, the message "There is a problem with this site's security certificate" appears. After rebooting my computer a couple of times, the date and time also remain incorrect - it seems as though the computer restarted assuming the time was midnight on 1st January 2010 despite the date and time settings being set for current local time. Any help appreciated - does my problem lie AVG, or my internet provider

Hello Graham.
Thank you for contacting us. We would like to inform you that the issue is not with AVG but it is with the date and time settings of your PC. Many website security certificate problems can be fixed by making sure your computer’s clock has the right time, day and year. At times the clock can get out of sync and make your web browser think the certificate isn’t valid. Thank you.