How to Run Multiple Copies of Mozilla Firefox Portable on Windows

Sometimes, you might want to run multiple copies of Mozilla Firefox for some purposes. For example, if you are playing Mafia Wars on Facebook, you have many Mafia Wars profile and you want to run *ahem* Mafia Wars Autoplayer Script *ahem* with different settings on each profile.

One of the easiest ways to run multiple copies of Mozilla Firefox is to use the Mozilla Firefox Portable Edition. But still, if you are trying to run multiple copies of Mozilla Firefox Portable on Windows, the default setting will prevent you from doing so and you will get the “Another instance of Firefox is already running. Please close other instances of Firefox before launching Mozilla Firefox, Portable Edition.” error. You can actually enable the option to run multiple copies of portable Mozilla Firefox in a few easy steps.

1. Extract Mozilla Firefox Portable as you normally would. In this example, I will use “E:\whiztech\App\FirefoxPortable-01\” as the path.

2. In the Mozilla Firefox Portable folder that you just extracted, navigates to Other > Source (in my case, “E:\whiztech\App\FirefoxPortable-01\Other\Source\”). Copy the file “FirefoxPortable.ini” to the root folder of the Mozilla Firefox Portable installation where “FirefoxPortable.exe” is located (“E:\whiztech\App\FirefoxPortable-01\”).

3. Next, open the the “FirefoxPortable.ini” with Notepad (or any other text editor). Change the value “AllowMultipleInstances” from “false” to “true” (without the “”) (1). Save the file.

4. Now, just make as many copies as you want from the portable Mozilla Firefox folder that you created in step 1 to 3. If you already have other portable Mozilla Firefox copies, you can just copy “FirefoxPortable.ini” that you’ve edited in step 3 and put it where “FirefoxPortable.exe” is located in the other portable Mozilla Firefox folders.

The bad part about this method is, you will have to update *each* portable Mozilla Firefox folder every time you wish to upgrade to newer version of Mozilla Firefox, add-ons or scripts.

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Tags: Firefox, Mozilla, Portable Browser, Tips, Windows