There are various instances when you may need to uninstall Mozilla Firefox from your computer. However, after reading this post until the end, you can get the task accomplished with the utmost ease. Mozilla
Firefox is one of the most preferred free and open-source web
browsers that has millions of users around the globe. Sometimes,
Firefox becomes completely unresponsive and you need to uninstall an
older version of the Mozilla Firefox so that you can download the
latest updated version of the browser. Before you contact the Mozilla
Firefox helpline number, read this post that shares information that
can help you to fix the problem. Let’s start! 

I Cannot Uninstall or Install Firefox: Error Description 

When your Firefox is not running correctly, you can completely remove it and download a fresh copy of the program. When you try to uninstall the browser, it gives an error message on the screen that reads –
“Firefox must be closed to proceed with the uninstall, please close
Firefox to continue.” There are various instances of this error
that you might see when uninstalling your Mozilla Firefox:

• I can't delete Firefox under "remove Programs".

• Unable to uninstall Firefox when it still says it's running.

• Cannot uninstall Firefox.

• Can't uninstall Firefox from my PC to reinstall the updated version.

• I cannot uninstall or install Firefox.

• How to uninstall Firefox?

These are some of the common instances of the error users experience when trying to uninstall Mozilla Firefox. When the error occurs, you may not be able to download a fresh copy of the Mozilla Firefox, and
therefore a persisting error remains unsolved in the browser. 

How to Uninstall Mozilla Firefox From Your Computer?

If you are unable to uninstall or remove an older version of your Mozilla Firefox, you need to perform a clean install for the software. A clean install is a process wherein, you remove Firefox
program files and then reinstall Firefox. Below are the steps:

• Go to the official Mozilla website and then download the latest version of your Firefox. 

• Once downloaded, save the setup file to an easily accessible location on your computer. 

• After the completion of the setup file download, you need to close Firefox windows. To do so, you need to click Exit from Firefox/File menu. 

• Thereafter, delete the Firefox installation folder from your computer. You can find this folder in the default locations of the following operating systems: 

Windows: 

• C:\Program Files\Mozilla Firefox

• C:\Program Files (x86)\Mozilla Firefox

Mac: 

• Go to the Applications folder to delete Firefox.

Linux: 

• If you have installed Firefox with the distro-based package manager, then you need to uninstall it the same way. However, if you have downloaded and installed the binary package from the official
  Firefox website, then you can simply remove the Firefox folder by
  navigating to your home directory. If you are facing any technical
  unease, reach out to an expert by dialling the Mozilla Firefox
  helpline number. 

• After uninstalling the Firefox, you can reinstall it using the setup file you have downloaded. 

• Go to the download location and double-click on the downloaded installation file. 

• When the installation wizard opens, follow the on-screen prompts carefully to get the task accomplished. 

• Once done, click on the Finish button to conclude the procedure. 

Now you may choose to directly open your Mozilla Firefox. 

FAQ's:

1: How to remove Firefox when it says – file in use? 

Sometimes, you may not be able to uninstall Mozilla Firefox from your computer as it says – File in use. In such a case, you need to Reboot in Safe Mode while ensuring that nothing runs on your device except the
system programs. By doing so, you should be able to uninstall
Firefox. If the problem continues: 

• Open the Firefox files from the Programs folder. 

• Windows: C:\Program Files

• C:\Program Files (x86)

• Mac: From within the Applications folder.

• Linux: Read out your user manual.

• Now delete the Firefox folder manually. 

• Thereafter, run a register scanner/repair to fix the issues. 

• Now reboot and the Firefox should have been removed.

2: Firefox is unable to load websites while other browsers can

Various reasons can prevent you from accessing a website using Mozilla Firefox. Faulty Firefox connection settings or Internet security settings blocking Firefox are some of the main reasons why Firefox
can’t load websites. In such a case, you need to remove Firefox
from your antivirus program’s list of the trusted programs and then
add it back. Also, configure your Internet security settings
correctly to keep the errors at bay. However, if the error continues
to trouble you, uninstall Mozilla Firefox from your computer and
reinstall a fresh copy of it on your device. 

3: How to uninstall Firefox using your device menu? 

Now that you know how to uninstall Mozilla Firefox from your computer, below are the steps to get the job done using your device menu: 

• First thing first, go to your device's Settings menu.

• Thereafter, you need to select Applications, Apps or Application manager (based on the label on your device).

• Next, tap on Firefox Browser for Android to see the available options.

• In the end, tap Uninstall to finish the task. 

If you are not comfortable with the steps, get in touch with the experts by dialling the Mozilla Firefox helpline number.