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Hard disk crashed, no back-up but saved all files. What do I need to restore new Firefox to original state?

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  • Last reply by cor-el

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I had a fatal hard disk crash on my laptop the other day. Good news is, it was only the boot sector--all my files and data were intact so have downloaded to another hard disk for safe-keeping while I load the OS onto the the fresh HDD.

Once I've loaded the new version of Firefox, what files do I need to find from the old data to restore Firefox to it's pre-crash state? Is this information (bookmarks, settings, etc.) recoverable at all? Am I hosed and need to start from scratch? No back-ups, unfortunately. But all system files and program files are there. Just don't know what is what and how to migrate (or if it's even possible).

Thanks, in advance.

I had a fatal hard disk crash on my laptop the other day. Good news is, it was only the boot sector--all my files and data were intact so have downloaded to another hard disk for safe-keeping while I load the OS onto the the fresh HDD. Once I've loaded the new version of Firefox, what files do I need to find from the old data to restore Firefox to it's pre-crash state? Is this information (bookmarks, settings, etc.) recoverable at all? Am I hosed and need to start from scratch? No back-ups, unfortunately. But all system files and program files are there. Just don't know what is what and how to migrate (or if it's even possible). Thanks, in advance.

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Firefox uses two locations for the Firefox profile folder. Location used for the main profile in "AppData\Roaming".

  • C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>\

Location used for the disk cache and other temporary files in "AppData\Local".

  • C:\Users\<user>\AppData\Local\Mozilla\Firefox\Profiles\<profile>\

The files in the cache area aren't important and do not need to be restored.

"AppData" (XP: Application Data; Mac: ~/Library; Linux: ~/.mozilla) is a hidden folder.


You need to recover the files in the main Firefox profile folder in "AppData\Roaming" and copy the data you really need to the current profile folder.

You can copy files like these to the current Firefox profile folder to recover specific data.

  • bookmarks and history: places.sqlite
  • bookmark backups: JSON backups in the bookmarkbackups folder
  • SQLite files like cookies.sqlite (cookies) and formhistory.sqlite (saved form data)
  • logins.json and key3.db (decryption key) for Passwords saved in the Password Manager
  • cert8.db and possibly cert_override.txt for (intermediate) certificates stored in the Certificate Manager
  • persdict.dat for words you added to the spelling checker dictionary
  • permissions.sqlite for Permissions and possibly content-prefs.sqlite for other Site Preferences
  • sessionstore.js for open tabs and pinned tabs and tab groups