If you are trying to get on to websites that you routinely visit and get a message that its certificate has expired or that it is a dangerous site, you are having a problem with certificates. You may try to check your security software program only to find that you are getting a certificate error there as well. While this problem seems daunting, like where to you even begin to solve this one? The solution might be nearby and take you less than a minute to fix.
Check the time and date on your computer! That's right. Sometime, for unknown reasons, the time and date change unexpectedly. If it is August 24, 2014 at 4:45 pm, your computer time and date may read: December 10, 2010 and 8:15 am. Reset the time and date. Perhaps even shut down and restart your computer, checking the ensure that the time and date are still correct. Many times, this will solve your certificate problems.