Firefox Install Stuck? Here are 8 Tested Methods to Fix it

by Loredana Harsana
Loredana Harsana
Loredana Harsana
Managing Editor
Loredana is a passionate writer with a keen interest in PC software and technology. She started off writing about mobile phones back when Samsung Galaxy S II was... read more
Fact checked by Alex Serban
Alex Serban
Alex Serban
Browser & Networking Expert
After moving away from the corporate work-style, Alex has found rewards in a lifestyle of constant analysis, team coordination and pestering his colleagues. Holding an MCSA Windows Server... read more
Affiliate Disclosure
  • When the Firefox installer remains stuck on now installing, you should check your temporary files or the privileges of your Windows account.
  • Make sure your antivirus or Windows Defender are not the cause of this issue.
  • Alternatively, consider switching to another great browser, faster, and more secure.
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Some users probably encountered various problems when trying to install Mozilla Firefox on their PC. One common error is that Firefox remains stuck on installing. If you are one of them, do not worry as we got your back.

In this article, we’ll offer you a list of the most common installation problems for Mozilla Firefox as well as solutions to similar error messages.

Why is Firefox taking so long to install?

The Firefox installer might be waiting for certain permissions to be granted from the user side. If you are not logged in as an administrator, issues like this might pop up.

Another cause might be Windows Defender. An antivirus software tool that was built by Microsoft to safeguard machines that use the Windows operating system is known as Microsoft Defender Antivirus.

It performs scans, identifies, and eliminates viruses, spyware, and malware, so assisting in the prevention of infection to the operating system.

However, sometimes it can misinterpret certain files as malware. Note that if you turn this feature off, your security will be at risk, so make sure to turn it back on as soon as possible.

How long should Firefox take to install?

It is possible that installing Firefox will take anything from a few seconds to five minutes, depending on the speed of your Internet connection. If it takes much longer than that, you need to take corrective action since this is not the usual.

Before trying the troubleshooting steps, let us tell you a few more tips when encountering similar issues:

  • Hmm, for some reason we could not install Firefox – There are times when the installation procedure does not complete and users get this message. If that’s your case too, note that you can’t have Firefox running during installation.
  • Firefox not installing on Windows 10 – If you’ve tried to install Firefox to no avail, check the setting to Prevent Accessibility Services from accessing your browser from the Privacy & Security panel.
  • Cannot install/reinstall Firefox keeps saying an old copy is running? – Uninstalling the old copy first isn’t always enough. Also, get rid of any leftovers and stubborn software with the help of the best uninstaller tools.
  • Firefox won’t install Windows 10 – This issue can sometimes be caused by your antivirus. To fix it, disable your antivirus and check if that helps.
  • Firefox installs stuck on downloading, housekeeping – Sometimes this issue can appear while trying to install Firefox using the standard installer. According to users, the solution is to download and use the full installer.
  • Firefox install takes forever – If your Firefox installation is slow, you might be able to fix the problem simply by trying to run it as an administrator. After doing that, check if the issue is still there.

Without further ado, let’s see what you can do if you can’t download Firefox on your device. Keep one reading!

Quick Tip:

In case you encounter this issue constantly and anything doesn’t seem to work, consider a change with Opera.

This personalized browser is your gateway to sound and fast navigation, with a very simple and uninterrupted installation. Hence, you can install and update the browser or import any data from Firefox.


Opera is a worthy alternative to Firefox and it offers smooth installation.

How do I fix Firefox installation if it’s stuck?

1. Reinstall Firefox

Sometimes you won’t be able to update Firefox at all, and your Firefox install might get stuck with Failed to read the configuration file. Please contact your system administrator message.

If this happens, your mozilla.cfg file might be damaged, and in order to fix the problem, it’s advised to reinstall Firefox.

In addition to uninstalling the application, you also have to remove all leftover files from Firefox’s installation directory.

Doing this manually can be a tedious task, therefore it’s always better to use an uninstaller software tool such as IObit Uninstaller. For more details, read our complete guide on how to use IObit.

2. Download the full installer

In order to distribute Firefox faster, Mozilla offers two types of installers, standard and full. The difference between the two is their size.

The standard installer is lighter, so it needs to download the setup files in order to install Firefox. This can sometimes cause the Firefox installation to get stuck.

On the other hand, the full installer, also known as Firefox offline installer, won’t download any additional files, instead, it will install Firefox right away.

This is a simple solution, and many users reported that it works, so be sure to try it out. You can get the full Firefox installer right away.

3. Check your permissions

  1. Press the Windows key + R and enter %localappdata%. Press Enter or click OK.local-data-run-w10 firefox stuck on now installing
  2. Locate the Temp folder, right-click it and choose Properties from the menu.temp-properties-w10 firefox stuck on now installing
  3. Select the Security tab from the top menu and click firefox stuck on now installing
  4. Click on Add.add-w10 firefox stuck on now installing
  5. In the white box write the word Users and click OK.users-ok-w10 firefox stuck on now installing
  6. Select Users from the Group or user names list and check Full control in Allow column. Now click Apply and OK to save changes.users-allow-w10 firefox stuck on now installing
  7. In addition to changing the permissions, some users are suggesting clearing all directories from the Mozilla updates folder. Thus, open a new File Explorer tab by typing File Explorer inside the Windows Search bar.
  8. Navigate to the following location but make sure to replace windowsreport with your username: C:\Users\windowsreport\AppData\Local\Mozilla
  9. Next, navigate to the updates directory and check whether you see any folders in there. Remove all of them and try to update or install Firefox again. Note that this solution also works when you are unable to install Mozilla Firefox in Windows 10.updates-w10 firefox stuck on now installing
  10. If you see any folders in there, remove them and try to update Firefox again.

4.  Try to update the browser manually

  1. Click the Menu icon in the top right corner and choose Help followed by About firefox stuck on now installing
  2. A new window will now appear and Firefox will check for updates. If any updates are available, they will be automatically installed.firefox-updating firefox stuck on now installing

Theoretically, Firefox is set to automatically install the updates, but sometimes various factors may prevent that. To check for updates manually, do as described above.

5. Run Firefox as an Administrator

If Firefox install gets stuck on your PC, perhaps the issue might be related to the missing privileges. To fix this issue, it’s required to run the setup file as an administrator.

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This is quite simple, and to do it, you just need to locate the setup file, right-click it and choose Run as administrator.

If you’re having problems updating Firefox, you just need to repeat these steps for firefox.exe and then try to update it again.

6. Disable Windows Defender

  1. Open Settings first by holding Windows and I and go to the Update & Security section.update-security firefox stuck on now installing
  2. Click Open Windows Security.serucity-open-w10 firefox stuck on now installing
  3. Go to the Virus & Threat protection section.virus-w10 firefox stuck on now installing
  4. Now click Manage settings.manage-settings-w10 firefox stuck on now installing
  5. Locate the Real-time protection option and disable it. You can also disable other options if you want.realtime-protection-w10 firefox stuck on now installing

Even if you don’t use a third-party antivirus, sometimes Firefox install can get stuck on your PC.

This can be caused by Windows Defender, and in order to fix the problem, you need to disable it as described above.

After disabling this option, try to install Firefox again. If Firefox installs successfully, be sure to enable Windows Defender once again.

7. Check your security software

If Firefox install gets stuck on your Windows PC, the issue might be your security software.

Sometimes certain antivirus features can interfere with your system, so it’s advised to disable these features. Here’s how to do that in many popular antivirus tools:


Here’s how to disable the secure connection feature from this antivirus:

  1. Open the dashboard of Avast.
  2. Click on Settings followed by Protection and Core Shields.avast-settings firefox stuck on now installing
  3. Navigate to Web Shield and uncheck the Enable HTTP Scanning box and click on the OK button to update this feature.https-enable-avast firefox stuck on now installing

This should stop your Avast antivirus from checking the security certificate of every website you access.


  1. Open the dashboard of Bitdefender. If you have the 2016 version, click on Modules. For an older version, you must click on the Protection firefox stuck on now installing
  2. Click on the Web Protection button.web-protection-bitdifender firefox stuck on now installing
  3. Disable the Scan SSL feature.


For ESET all you have to do is to enable the SSL/TSL protocol filtering feature.

  1. Open ESET antivirus and select Setup followed by Advanced setup.setup-eset firefox stuck on now installing
  2. Click on Web and email followed by SSL/TSL, Enable SSL/TSL protocol filtering, and OK.web-eset firefox stuck on now installing
  3. Restart the computer to configure the antivirus filter.


Kaspersky has a function that can be disabled to stop filtering the websites and it is very easy to do this.

  1. Open the dashboard of the antivirus and click on the Settings button from the bottom-left.settings-kasper firefox stuck on now installing
  2. Scroll down the left menu and click on Network settings.
  3. If you are using the 2016 version, uncheck the Do not scan encrypted connections box from the Encrypted connections settings section. For an older version just, uncheck the Scan encrypted connections upon request from protection components firefox stuck on now installing
  4. Reboot your system to configure your antivirus software.

If disabling this feature doesn’t solve the problem, completely disable your antivirus. If the issue still persists, remove your antivirus and check if that helps.

In case removing the antivirus solves the problem, this might be a perfect opportunity to consider switching to a different antivirus solution.

There are many Windows 10 compatible antivirus software that won’t interfere with your system while providing great system protection.

Alternatively, check out the best antiviruses that are suited for Windows 11 in case you’re using this OS iteration.

We hope these methods will help you out with any issues you might have when trying to install the Firefox browser, especially when the installer remains stuck on now installing.

If none of these methods helped you, we strongly recommend you to get in touch with the Support department of Mozilla. And as always, feel free to share your thoughts with us in the comments section below. Thanks for reading!

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