How to use multiple versions of Firefox on the same computer
Last updated on April 4, 2011, 20:33 by Sebastian Mihai
With the release of Firefox 4, it will be useful to be able to get multiple versions of Firefox to co-exist peacefully on the same machine. Here's a summarized tutorial on how to achieve this; it assumes that a version of Firefox is already installed on your system.

STEP 1: Create a profile for FF4

Different versions of FF save their profiles in the same place. Moreover, if the same profile is used by multiple versions of FF, it may be corrupted. Our goal is to have at least one profile for each version of FF we're installing.

From START > RUN, enter (changing the path to your already installed FF directory as needed):
"C:\Program Files\Mozilla Firefox\firefox.exe" -P -no-remote
and click OK. This brings up the FF profile manager.

Click Create Profile, and name your new profile something indicative of the version with which it will be used, such as profile_4_X_XX_latest.
Click Exit.

STEP 2: Installation of FF4

Download and start the FF4 installer.
Choose Custom installation. It's up to you where you install it; I chose C:\Program Files\Mozilla Firefox 4

STEP 3: Profile selection from shortcut

I chose to get a FF shortcut on my desktop. This shortcut can be edited so that it starts FF with a specific profile. In my case, I changed the Target field in the shortcut properties to:
"C:\Program Files\Mozilla Firefox 4\firefox.exe" -P profile_4_X_XX_latest
Obviously, you can go back and add the -P parameter to all your other FF shortcuts, so that each version of FF will start up its own specific profile. If you forget the names of your profiles, you can bring up the FF profile manager to check them (see STEP 1).

That's about it.
If you use the materials on this page, or any other page on this web site, you do so at your own risk. They are provided "as is". No warranty is provided or implied. I neither guarantee that the materials will work, nor that they will not be harmful in any way.

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