Custom installation of Firefox on Windows

How to download and install Firefox on Windows explains how to install Firefox with standard options using an online (stub) installer. You may decide instead to use the full, offline installer, available from the Systems and Languages download page, so that you can choose a language, a 32-bit or 64-bit Firefox version on 64-bit Windows, or custom installation options.

This article explains the custom options that are available in the Firefox full, offline installer.

Custom installation


When you run the full installer, the Mozilla Firefox Setup Wizard will open. After clicking Next you can choose a Standard or Custom installation. The Standard setup will be selected by default.


A Custom setup lets you choose the folder where Firefox program files will be installed, as well as which shortcuts to create. These options are not available in a Standard setup. Select the Custom setup type and click Next.

Choose where Firefox is installed

The next step is where you can choose a different Destination Folder, which is where the Firefox program will be installed.


C:\Program Files\Mozilla Firefox\ is the default folder path on 32-bit Windows. It's also the default location on 64-bit Windows when the 64-bit Firefox version is installed.

When the 32-bit Firefox version is installed on 64-bit Windows, the default folder path is C:\Program Files (x86)\Mozilla Firefox\

You can change the folder where Firefox will be installed either by manually typing the location of another folder on your computer or you can click Browse... to select a new folder.

  • Space required: The amount of space on your hard drive that's needed to install Firefox.
  • Space available: The amount of space available on your hard drive.

Click Next to continue.

Choose optional components


In the next screen you can choose whether to install the optional Mozilla Maintenance Service which allows application updates to occur in the background, without requiring you to click Yes in the Windows User Account Control (UAC) dialog. For more information, see What is the Mozilla Maintenance Service?.

Note: This option may be missing in some cases (for example, the Mozilla Maintenance Service may already be installed on your computer).

Choose shortcuts


  • On my Desktop: You can choose to create a Firefox shortcut icon on the Windows Desktop.
  • In my Start Menu Programs folder: This will create a Firefox shortcut icon in the Windows Start Menu Programs folder.

After choosing which Firefox program shortcuts to create, click Next.


The Summary that comes up next will display the folder location where Firefox will be installed and normally includes an option to set Firefox as the default browser.


  • Check mark Use Firefox as my default web browser if you want Firefox to start up when you open a link in your mail application, an Internet shortcut, or HTML document.

This option will be missing in some cases (for example, you don't have permission to set Windows registry keys). For more information about setting Firefox as the default web browser, see Make Firefox your default browser.

Note: The option to set Firefox as the default browser may also be missing if you are reinstalling over an existing Firefox version and Firefox is already the default browser. In such cases you'll see an Upgrade button instead of an Install button, as shown below:

After you click the Install (or Upgrade) button, Firefox will start installing. After the installation is completed, the "Completing the Mozilla Firefox Setup Wizard" screen is displayed.


Click Finish. This will start Firefox unless you first clear the "Launch Firefox now" checkbox.

Congratulations, you are done installing Firefox!

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