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Restoring previous PC Firefox data

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  • 最後の返信者: cor-el

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Hey,

swapped PC today, meaning full format and everything new, tried logging in to Firefox but I'd forgotten my password so I reset it, does that mean everything saved on my account got reset?

Could I somehow verify my identity as the same user and get everything I had going on my Firefox account on a different PC back?

Hey, swapped PC today, meaning full format and everything new, tried logging in to Firefox but I'd forgotten my password so I reset it, does that mean everything saved on my account got reset? Could I somehow verify my identity as the same user and get everything I had going on my Firefox account on a different PC back?

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Unless you have synced setup that will time take to restore back from Firefox sync systems. If not then there is nothing that can be done since a Full format wipes clean any data. And if you forget your password there's nothing that can be done and if reset doesn't work that is a lost account. Reset or changed password will wipe clean any sync system that isn't the original device that contain the data.

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If I take the C: drive from my old PC and plug it in to my new one, can I extract any of the relevant information from the Firefox folder there?

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Resetting the password for the Firefox Account because you do not remember the password will remove all data stored on the Sync server because this password is used to encrypt your data before it is uploaded to the Sync server and only this password or a possible recovery key can decrypt this data.


You can copy certain files with Firefox closed from another profile folder to the current profile folder to transfer/recover/backup your personal data. Note that best is to avoid restoring a full profile folder.

The profile is in this hidden location:

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

You can use the button on the "Help -> More Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page (Root directory).


  • bookmarks and history: places.sqlite
  • favicons: favicons.sqlite
  • bookmark backups: compressed .jsonlz4 JSON backups in the bookmarkbackups folder
  • cookies.sqlite for the Cookies
  • formhistory.sqlite for saved autocomplete Form Data
  • logins.json (encrypted logins) and key4.db (decryption key and primary password) for logins saved in the Password Manager
  • cert9.db for certificates stored in the Certificate Manager
  • persdict.dat for words added to the spell checker dictionary
  • permissions.sqlite for Permissions and possibly content-prefs.sqlite for other website specific data (Site Preferences)
  • sessionstore.jsonlz4 for open tabs and pinned tabs (see also the sessionstore-backups folder)