After reinstall, SSL certificates not accepted.

Hello there!

I've reinstalled my Macbook Air (Mid 2012, OS X Mountain Lion 10.8.2) due to a problem when I lost my password.
When I launched an app like Safari, Mail or Chrome, I've experienced the same problem. Pages using the SSL encryption were unsupported, not working. It shows the problem with the certificate which is not acceptible, old.

Please, help me out there.

In the meantime, I will be using Firefox, which works just fine (strange!).

Thank you all very much!

A.