Separate Issue; Your System Details shows; Installed Plug-ins Adobe PDF Plug-In For Firefox and Netscape 11.0.0 Adobe PDF Plug-In For Firefox and Netscape 11.0.9 <br>Having more than one version of a program may cause issues. You must remove the older programs. Then get the current full installer. Security Issue: Update your '''[http://get.adobe.com/reader/ Adobe Reader Version 2015.016.20039]''' '''Note: Other Software''' is offered in the download. ------------ There is security software like Avast and Kaspersky and BitDefender and ESET that intercept secure connections and send their own certificate. http://www.ehow.com/how_11385212_troubleshoot-reset-connection-firefox.html https://support.mozilla.org/en-US/kb/server-not-found-connection-problem https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can https://support.mozilla.org/en-US/kb/firefox-and-other-browsers-cant-load-websites https://support.mozilla.org/en-US/kb/secure-connection-failed-error-message https://support.mozilla.org/en-US/kb/connection-untrusted-error-message '''http://kb.mozillazine.org/Error_loading_websites''' https://support.mozilla.org/kb/troubleshoot-SEC_ERROR_UNKNOWN_ISSUER '''This Connection is Untrusted''' is sometimes caused because the computer system clock is wrong. Check the time / date / time zone settings.