How to change your default browser on Windows XP to portable Firefox (or any other portable browser)


This posting will describe how to change your default system browser on Windows XP to a portable version of Mozilla Firefox using a free program called DefaultBrowser, doing so reversibly and without installing the non portable version.

The same process described here could be used to change your default browser to any portable (or non portable) browser.

[Editor’s note: this posting was contributed by Freewaregenius reader Elioz Hefer; to whom I offer my extreme thanks and gratitude].

After a period of using MS Internet Explorer, my computer’s response time has become slower and I have encountered repeated problems of being thrown out from IE8 (especially). I have come to the conclusion that a clutter of addons has caused it, and resetting to default regrettably hasn’t been much help.

I therefore turned to the portable version of Mozilla firefox, with the thought that I would prefer to preserve my PC hygiene as much as possible. I have learned in time that my most valuable asset is the speed and quick response time of a computer, and therefore I try to avoid fixed installations. I also found that virtualizations such as Altiris SVS help but do not completely block remains of programs, and the same goes for programs that monitor or record program installations such as Magical Uninstall.

Firefox Portable Edition is the popular Mozilla Firefox web browser bundled with the Launcher as a portable app, so you can take your bookmarks, extensions and saved passwords with you. Mozilla Firefox Portable Edition can be copied to a thumb drive so that you can use it whereever you go.

One problem though is that Firefox Portable Edition does not register itself with the system, and
thus cannot be set as the default browser using the GUI. Whenever turning to a new Url (within Portable Firefox or from library links I have previously saved, my PC would continuously opens IE8. Which is why I started looking for a way to set the portable version of Firefox to the default browser without installing the regular non portable version and the least degree of integration with my system.

The solution came in the form of very elegant program called DefaultBrowser written by Ramesh of “Ramesh’s site“, a resource dedicated to troubleshooting windows XP. This small utility can set the default browser according to user preference. What’s more, it is reversible and doesn’t install itself on the system that I could notice. Download it here.

Here is how to set Firefox Portable as the default browser for your user profile in Windows XP.

  1. Download DefaultBrowser and unzip to the folder of your choice
  2. Run the executable and select Firefox Portable from the list of browsers (see screenshot above) then click Apply.
  3. In the Browse dialog box, select the location where the executable FirefoxPortable.exe is located.
  4. That’s it. Very quickly and like magic Firefox Portable is now set as the default browser for your user account.


  1. If your desired browser is not on the list: in this case click browse button in the “for other browsers” section and point to the desired browser executable.
  2. DefaultBrowser doesn’t change the IE shortcut in the “Quick Launch” menu which will still open Internet Explorer. Therefore you must manually put a shortcut of the Portable Firefox executable in the quick launch folder. To do that click the quick launch area and then choose Open folder, you can then drag create shortcuts in there or remove the ones you don’t want (I wouldn’t delete the explorer Icon from that folder in case you wish to reverse things).
  3. Reversing this process: is done is done very easily by opening the small DefaultBrowser utility and choosing the reset button.
  4. Important: If you’re using Mozilla Firefox Portable Edition from a USB disk: whenever the drive-letter for the USB disk changes, you’ll need to re-register FirefoxPortable.exe using the DefaultBrowser utility. For instance, the drive-letter for your USB disk may change when adding additional hardware in your system.

That’s it, enjoy!

Version Tested: 1.8

Compatibility: Windows XP.

Go to the DefaultBrowser page to download the latest version (approx 31K).