A personal firewall is a security program that oversees all of your computer's connections to the Internet. It may be included as part of an Internet security suite, or it may be a free-standing program. Most personal firewalls will deny Internet access to any program, or a new version of any program, unless you have specifically allowed access. This article will help you find information about configuring your firewall to work with Firefox.
If you know which firewall or Internet security suite you are running, skip to the next section.
Depending on your Windows version, do the following:
If you can't still detect your firewall with the above steps, try to run Enum Process (not created by Mozilla) that is an application that detects many common firewalls:
Refer to the Apple documentation.
Go to your distribution's firewall documentation.