However, there may be other causes for this error as given above. If the site is on the domain and is known to be legitimate, this is most likely the issue and an exception can usually be safely set. There is a possiblity that the certificate has expired.See the following document: Windows Defender - Running an Antivirus Scan If your system time is correct and you are receiving this warning, it is recommend you run a full virus scan. This can be a legitimate security warning if your computer is infected with malware or you have visited a compromised site. Windows 7, 8, and Vista - Changing the System Date and Time.To reset the system clock, see one of the following documents: Often the cause of the problem is your system clock is off. Here are a few browser specific security certificate errors: Firefox This means that web browsers which are not using the new ipsCA root certificate will encounter one of the errors shown below when viewing a secure page that uses an ipsCA certificate. The root certificate for ipsCA expires on December 29, 2009. Note: Many web sites and applications on campus are signed using certificates provided by ipsCA, a Certificate Authority that provides certificates to educational institutions.
