I'm sorry you have having trouble with Firefox, can you please expand a bit more on what exact error you are seeing?

Also, please try running through these articles. They can help you fix any additional errors in Firefox:

• Refresh Firefox - reset add-ons and settings
• Problematic Certificates

You can check the date and time and time zone in the clock on your computer: (double) click the clock icon on the Windows Taskbar.

• https://support.mozilla.org/kb/Secure+Connection+Failed

You can retrieve the certificate and check details like who issued certificates and expiration dates of certificates.

• Click the link at the bottom of the error page: "I Understand the Risks"
• Let Firefox retrieve the certificate: "Add Exception" -> "Get Certificate"
• Click the "View" button and inspect the certificate and check who is the issuer.

You can see more details like the intermediate certificates that are used in the Details tab.

Who is the issuer of the certificate?

Can you attach a screenshot of the certificate Viewer?

• http://en.wikipedia.org/wiki/Screenshot
• https://support.mozilla.org/kb/how-do-i-create-screenshot-my-problem

• Use a compressed image type like PNG or JPG to save the screenshot
• Make sure that you do not exceed the maximum size of 1 MB

I just want to explain the reason for the certificate check that cor-el suggested:

Several different security programs intercept your web requests to filter them for security threats. In order to do this, they have to present Firefox with a fake certificate in place of the real one, otherwise the traffic is encrypted and therefore cannot be checked. Programs with this feature include avast, Bitdefender, ESET and Kaspersky. Firefox needs to be set up to trust your security software to read all of this traffic. Often the program can do this automatically but in some cases you may need to do it manually (the steps vary depending on what software you use).

Unfortunately, there also is malware that sites on your computer and does the same thing: it reads all your secure traffic. Why it does this and what it does with the information we don't know, but you will definitely want to remove it. Because Firefox has a separate certificate store from the one used by IE and Chrome, this malware can run quietly on your PC for years and you never know until you install Firefox.

To sort out what's going on, please take a minute to check the certificate as cor-el described and let us know what you find.

Finally, I will add that if Firefox worked normally until the last update, it's possible that you used the Refresh feature during the update. This can occur when Firefox reports it is running slowly and says you can speed it up by restoring some default settings. If you click that button, your settings folder is moved to the desktop inside an Old Firefox Data folder, and all your previously saved security exceptions are cleared. If you see an Old Firefox Data folder on your desktop with a recently updated semi-randomly-named folder inside, that might be what brought on this problem.

Also you appear to be posting with Windows 7 as your Operation System or OS as Firefox itself is just a web browser you use as a way to browse the internet.

If you can't inspect the certificate via "I Understand the Risks" then try this:

Open this chrome URI by pasting or typing this URI in the location/address bar to open the "Add Security Exception" window and check the certificate:

• chrome://pippki/content/exceptionDialog.xul

In the location field type/paste the URL of the website

• retrieve the certificate via the "Get certificate" button
• click the "View..." button to inspect the certificate in the Certificate Viewer

Check who is the issuer of the certificate.

You can inspect more details like the certificate chain in Details tab of the Certificate Viewer.