Portable Firefox is a fully functional package of Firefox optimized for use on a USB key drive. It has some specially-selected optimizations to make it perform faster and extend the life of your USB key as well as a specialized launcher that will allow most of your favorite extensions to work as you switch computers. It will also work from a CDRW drive (in packet mode), ZIP drives, external hard drives, some MP3 players, flash RAM cards and more.

To install, just download the ZIP and unzip it to the root directory of your USB drive. It will create a "firefox" directory and all the requisite directories underneath. To use Firefox on your drive, launch it with the PortableFirefox.exe file in the firefox directory. DO NOT launch the firefox.exe file directly, as this will create a profile on your hard drive or use an existing one. Additionally, be sure you've closed any local copies of Firefox and that they've finished shutting down. Otherwise, a new window of your local install will be launched. This is a feature of Firefox itself to prevent multiple copies running at the same time.

Mozilla Firefox - Your web, the way you like it: high performance, easy customization and advanced security.

Features:

Anti-Malware
Firefox protects you from viruses, worms, trojan horses and spyware delivered over the Web. If you accidentally access an attack site, it will warn you away from the site and tell you why it isn’t safe to use.

Anti-Phishing
Shop and do business safely on the Internet. Firefox gets a fresh update of web forgery sites 48 times in a day, so if you try to visit a fraudulent site that’s pretending to be a site you trust (like your bank), a browser message—big as life—will stop you.

Instant Web Site ID
Want to be extra sure about a site’s legitimacy before you make a purchase? Click on a site favicon for an instant identity overview. Another click digs deeper: how many times have you visited? Are your passwords saved? Check up on suspicious sites, avoid Web forgeries and make sure a site is what it claims to be.

Forget This Site
Having second thoughts about having visited a certain Web site? With this feature, you can remove every trace of that site from your browser—no questions asked!

Parental Controls
Enforce parental control settings you’ve entered on Windows 7 — stop unwanted downloads and more.

Outdated Plug-In Detection
Some web pages require that you install small applications called plugins to watch videos, play games or view documents. These plugins are written by other companies, and it can be hard to make sure they’re always up to date. Since outdated plugins are a security risk, Firefox will let you know when you have a plugin that’s vulnerable to attack and direct you to the right site to get the updated version. View our plugin check page.

Clear Recent History
Clear all your private data or just your activity over the past few hours with a few quick clicks. You have full control over what to delete, and then your info is gone for good—on your own computer or the one at your local library. It’s that easy.

Private Browsing
Sometimes it’s nice to go undercover, so turn this feature on and protect your browsing history. You can slip in and out of private browsing mode quickly, so it’s easy to go back to what you were doing before as if nothing ever happened. It’s great if you’re doing your online banking on a shared computer or checking email from an Internet café.

Customized Security Settings
Control the level of scrutiny you’d like Firefox to give a site and enter exceptions—sites that don’t need the third degree. Customize settings for passwords, cookies, loading images and installing add-ons for a fully empowered Web experience.

Add-ons
Firefox looks for a secure connection before installing or updating add-ons, 3rd party software, and Personas.

Anti-Virus Software
Firefox integrates elegantly with your Windows antivirus software. When you download a file, your computer’s antivirus program automatically checks it to protect you against viruses and other malware, which could otherwise attack your computer.