A personal firewall (e.g., the Norton firewall and Zone Alarm) is a security program that controls access to the Internet.
The firewall may be a freestanding program, or it may be part of an Internet security package.
If you are using the Norton 360 Internet security suite and your Mozilla application cannot access the internet, check your Firewall Protection settings.The following instructions are based on the Symantec articles, Cannot use a specific program after installing Norton 360 and My Internet-enabled application or device is not able to access the Internet after installing Norton 360 2.0 To modify the Firewall Protection settings for your Mozilla application, The firewall component of Norton Internet Security (NIS) must be configured to allow updated programs to use the Internet.If your Mozilla application cannot access the Internet, follow these instructions (from the Symantec support articles, Some Internet-enabled programs can no longer access Internet after installing Norton Internet Security 2008 and Cannot use a specific program after installing Norton Internet Security 2007): Allow access to the program in Firewall Program Rules For other versions of Norton Internet Security, see this Symantec Knowledge Base article as well as Configuring Norton Internet Security (Firefox Support) and this forum post.Users also have the option of blocking domain-name service (DNS) for some programs but not others. The following instructions are from the article, Firewall rules for applications in Kaspersky Internet Security 7.0: Using the Delete button, you can delete a rule for the selected application (e.g., Firefox.exe).If you need more help, read Configuring Kaspersky Internet Security (Firefox Support) and this web page or visit Kaspersky Technical Support and Knowledge Base. Comodo Firewall is no longer offered for download as a standalone application.