What Is Mozilla Maintenance Service And Do I Need It?

Mozilla Maintenance Service was originally introduced for Firefox only back in 2012. It is now used by both Firefox and Thunderbird, plus other Mozilla products.

We’ll review what it is and explain how you can disable or remove it if you really wish – although it is usually best left alone.

What Is Mozilla Maintenance Service?

It is an optional background Windows service (program) which allows Firefox or Thunderbird to install updates without requiring you to see (and click ‘Yes’ in) the User Account Control (UAC) window in Windows 10/8/7 and Vista.

[Note: even though XP does not have UAC, this Service is still installed – the aim was to use it to further streamline the update process but there is no evidence this ever happened for XP]

The Service therefore allows ‘silent’ updates of Firefox and Thunderbird (or almost silent – they still need to be restarted to apply the update).

It works as follows: once Firefox has downloaded an update, it starts up the Service which automatically gets permission from Windows to allow the update to be installed (without a UAC dialog window asking you for permission).

Until that time, the Service doesn’t run so it doesn’t use any computer resources or slow down your computer – once the update process begins, the Service has done its job and therefore closes again.

How It Helps Silent Updates

If you have Firefox updates set to ‘Automatically install updates’ and the Mozilla Maintenance Service is ticked (‘Use a background service’ as shown in the example below) then future updates to Firefox should be almost silent:

Mozilla Maintenance Service option

  1. Firefox automatically checks for updates
  2. If an update is available it is downloaded in the background
  3. Firefox then starts the Mozilla Maintenance Service to allow the update to be installed without UAC prompts
  4. The update is installed and a message appears asking you to restart Firefox in order for the update to be applied

How To Disable Or Uninstall Mozilla Maintenance Service

Note: most users should leave it enabled to ensure that future Firefox updates (including security and stability fixes) are installed automatically. As the Service only runs when needed (usually at 6 week intervals when a new version is released) it won’t slow down your computer.

However, if you really do want to be prompted by UAC to authorize Firefox updates before they can be installed:

Disable Mozilla Maintenance Service:

  • From the Firefox menu bar click ‘Options’
  • Scroll down the General options list to the ‘Firefox Updates’ section (shown in the picture above)
  • Un-tick the box next to ‘Use a background service to install updates’

Uninstall Mozilla Maintenance Service:

Or, you can completely uninstall the Service like any other program – from Programs and Features (Windows 10/8/7/Vista) or Add/Remove Programs (XP).

Note: if you uninstall the Service it will not be installed again by future updates – as noted in a Mozilla tech note, manually uninstalling it applies a value of ‘Attempted=1’ to the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\MaintenanceService in which case the Service will be omitted from future updates.

So, if you wanted it to be reinstalled by a future update, you would have to delete the registry entry of ‘Attempted=1’ first.

Technical Details Of Mozilla Maintenance Service

It appears as ‘Mozilla Maintenance Service’ in the list of Windows Services (to find it, type services.msc in the Windows 10/8/7/Vista search box and click on Services.msc in the search results)

The startup type is ‘manual’ i.e. it only ever runs when called upon by Firefox in the event of a new update (and it closes immediately afterwards).

The actual file name of the program is ‘maintenanceservice.exe’ and it is usually located in the C:\Program Files\Mozilla Maintenance Service\ directory.

If you have both Firefox and Thunderbird, you will still only have 1 instance of the Service installed – it is used by both programs.


Mozilla Maintenance Service helps make Firefox and Thunderbird updates automatic and silent so you can forget about having to check for or install new updates manually.

This is especially useful if there are urgent security updates or stability fixes (outside of the normal 6 weekly update cycle) which you might otherwise miss out on.

If you still use Windows XP (which doesn’t have UAC) there appears to be little reason to keep the service. But, as it only runs every few weeks, there is very little to be gained from uninstalling it either.

Found this article useful? Why not check out our other Firefox articles such as how to browse Google by name for quicker searches in the address bar, search bar or context menu.

2 thoughts on “What Is Mozilla Maintenance Service And Do I Need It?”

  1. I close firefox on exit and the next day it tells me firefox is still running and I cant get into it and have to restart my PC to get into firefox I am running Norton 2013 internet security and have run all the scans and am clean can you help me with this problem

    • If Firefox is still running in the background – end the Firefox process in Task Manager to avoid having to restart the PC.

      However, you need to find the cause – most likely due to a faulty extension (add-on) so you should troubleshoot them i.e. disable them all and see if the problem reoccurs then enable each add-on one by one until you find the one that causes Firefox to hang.

      For more detailed suggestions, see Firefox Support on this topic – http://support.mozilla.org/en-US/questions/845252

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