Check the connection settings. *Tools > Options > Advanced : Network : Connection > Settings If you do not need to use a proxy to connect to internet then select "No Proxy" if the default "Use the system proxy settings" setting doesn't work. See "Firefox connection settings": *https://support.mozilla.com/kb/Firefox+cannot+load+websites+but+other+programs+can ---- Please update Firefox to the latest version via "Help > Check for Updates or Help > About Firefox"<br /> The Firefox 3.5.5 version that you use is no longer maintained with security and stability updates.<br /> Using unsupported Firefox versions is at your own risk and makes you vulnerable to attacks.<br /> Users of no longer supported Firefox versions are strongly recommended to update to the latest release that is supported by their system. *Firefox 7.0.x: http://www.mozilla.com/en-US/firefox/all.html *Firefox 3.6.x: http://www.mozilla.com/en-US/firefox/all-older.html ---- *http://en.wikipedia.org/wiki/Vulnerability_(computing) *http://www.mozilla.org/security/known-vulnerabilities/