What is a security certificate and why would Internet Explorer report issues with security certificates?
Web certificates, sometimes known as SSL Certificates verify a site you are going to really is the site it claims to be. Certificates can also help encrypt data between your computer and the site you are visiting. In order to verify a site is who it claims to be, the company hosting the site will use certificates to verify the server name and owner information.

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A problem comes in on some systems where the company hosting the site didn’t pay for a 3
rd party verification and instead used a so called “self-signed” certificate. Site administrators can easily do this with
Windows and Apache systems to save costs and time, but the end result is that end users going to the site will receive an error messages – most likely “There is a problem with this website's security certificate” when viewed in Internet Explorer 7 or 8 (Figure 1).
In other circumstances you may find the site name and site registered in the certificate don’t match. In this case you’ll receive the same Internet Explorer warning regarding a site certificate mismatch error.
As mentioned above, there are of course legitimate reasons why these issues crop up, so why would Microsoft force Internet Explorer to warn you whenever one of these scenarios popped up? It all boils down to malicious sites. Spammers and other malicious sites may use mismatch techniques to trick you into entering a site that seems legitimate but really isn’t.
Now that you should have a better understanding of what a site certificate is, why they are used and why Internet Explorer gives you a warning, I’ll show you how to bypass these warnings.