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Can FireFox be uninstalled and reinstalled without losing settings, preferences and bookmarks?

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  • 2 have this problem
  • 2223 views
  • Last reply by ranchwoo

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All of a sudden, I am no longer directed to my homepage when opening Firefox. All I get is "The address isn't valid". Also, when I choose options, new window, new private window and Find, I also get the error "The address isn't valid".

I refreshed Firefox, which didn't help, disabled add-ons, checked for updates and opened in safe mode, none of which helped. I have run various malware programs and virus scans and came up empty from that end.

I was thinking of uninstalling Firefox and reinstalling, but I am afraid that I will loose my bookmarks, settings, preferences, etc. Any suggestions?

All of a sudden, I am no longer directed to my homepage when opening Firefox. All I get is "The address isn't valid". Also, when I choose options, new window, new private window and Find, I also get the error "The address isn't valid". I refreshed Firefox, which didn't help, disabled add-ons, checked for updates and opened in safe mode, none of which helped. I have run various malware programs and virus scans and came up empty from that end. I was thinking of uninstalling Firefox and reinstalling, but I am afraid that I will loose my bookmarks, settings, preferences, etc. Any suggestions?

Chosen solution

Yes! Here's a good way to replace Firefox's program files without disturbing your settings:

Clean Reinstall

We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent, corrupted, or alien code files). As described below, this process does not disturb your existing settings. Do NOT uninstall Firefox, that's not needed.

(1) Download a fresh installer for Firefox 39.0 from https://www.mozilla.org/firefox/all/ to a convenient location. (Scroll down to your preferred language.)

(2) Exit out of Firefox (if applicable).

(3) Rename the program folder, either:

(64-bit Windows folder names)

C:\Program Files (x86)\Mozilla Firefox

to

C:\Program Files (x86)\OldFirefox

(32-bit Windows folder names)

C:\Program Files\Mozilla Firefox

to

C:\Program Files\OldFirefox

(4) Run the installer you downloaded in #1. It should automatically connect to your existing settings.

Do "internal" pages work normally again?

Note: Some plugins may exist only in that OldFirefox folder. If something essential is missing, look in these folders:

  • \OldFirefox\Plugins
  • \OldFirefox\browser\plugins
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Chosen Solution

Yes! Here's a good way to replace Firefox's program files without disturbing your settings:

Clean Reinstall

We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent, corrupted, or alien code files). As described below, this process does not disturb your existing settings. Do NOT uninstall Firefox, that's not needed.

(1) Download a fresh installer for Firefox 39.0 from https://www.mozilla.org/firefox/all/ to a convenient location. (Scroll down to your preferred language.)

(2) Exit out of Firefox (if applicable).

(3) Rename the program folder, either:

(64-bit Windows folder names)

C:\Program Files (x86)\Mozilla Firefox

to

C:\Program Files (x86)\OldFirefox

(32-bit Windows folder names)

C:\Program Files\Mozilla Firefox

to

C:\Program Files\OldFirefox

(4) Run the installer you downloaded in #1. It should automatically connect to your existing settings.

Do "internal" pages work normally again?

Note: Some plugins may exist only in that OldFirefox folder. If something essential is missing, look in these folders:

  • \OldFirefox\Plugins
  • \OldFirefox\browser\plugins
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What is the current home page setting?

You can find the home page setting here:

  • Tools > Options > General > Startup: Home page

You can use the SearchReset extension to reset some preferences to the default values.

Note that the SearchReset extension only runs once and then uninstalls automatically, so it won't show on the "Firefox > Add-ons" page (about:addons).

You can check for problems with preferences.

Delete possible user.js and numbered prefs-##.js files and rename (or delete) the prefs.js file to reset all prefs to the default value including prefs set via user.js and prefs that are no longer supported in the current Firefox release.

You can use this button to go to the current Firefox profile folder:

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Thanks, the clean install appears to have worked and all my bookmarks and setts are as well.