hi, are you putting a preconfigured firefox profile in place for these installations? if so, then please try to put the following line into the prefs.js file:

user_pref("browser.disableResetPrompt", true);

Hi,

No I am not using a preconfigured profile.

I just want to make sure than when deploying Firefox on a computer that has had it installed before, it does not come with this prompt.

ok, the you might want to use autoconfig - that's a way to set certain preferences in all firefox profiles by placing some files within the firefox installation folder: Customize Firefox using AutoConfig

in the firefox.cfg you can put these two lines:

//
lockPref("browser.disableResetPrompt",true);

...then the message won't be shown on the first run of firefox after installation, regardless if there is an existing old/unused profile in place already.

Hi,

Thank you for your help so far. The message is not shown at the first run of Firefox, but during installation, which is supposed to be silent.

I need to silently install Firefox without seeing the message.

Is Firefox getting launched at the end of the installation?

The resetUninstalled.message seems to be related to resetSupported()

• https://dxr.mozilla.org/mozilla-release/source/toolkit/locales/en-US/chrome/global/resetProfile.properties
• https://dxr.mozilla.org/mozilla-release/source/browser/components/nsBrowserGlue.js#897
• https://dxr.mozilla.org/mozilla-release/source/toolkit/modules/ResetProfile.jsm#21

Services.policies.isAllowed("profileRefresh") determines whether to show this message. Otherwise you would have to remove or hide existing profiles during the installation.

Thank you for your help. This describes the exact message I am seeing:

1. LOCALIZATION NOTE (resetUninstalled.message): %S is brandShortName.

resetUninstalled.message=Looks like you’ve reinstalled %S. Want us to clean it up for a fresh, like-new experience?

How do I build an installation string that will not show this message?

Can you post a screenshot of what you are seeing? I'm still not clear whether this is coming from Firefox or the installer.

So we think you're trying to use silent mode on the stub installer, but that doesn't work (and it presents the message). You should be using the full installer:

https://www.mozilla.org/en-US/firefox/all/

The message pops up during installation and asks if it needs to clean up files left behind for a fresh experience.

Now the good part: Your suggestion about the full installer hals solved the issue and Firefox now installs completely silent!

Thank you for your help.