Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox on Windows 10 transferring %AppData%...Profiles folder to new laptop but Firefox says it can't find my profile and closes.

  • 3 replies
  • 0 have this problem
  • 18 views
  • Last reply by simon151

more options

The solution of physically copying the Profiles folder seems to be officially endorsed by Mozilla but when I tried it, FF failed to start up displaying an error message that it could not find my profile and closing. I am trying to set up a new PC for my wife's exclusive use, so the Profiles folder in question was from a shared PC with both of us having our own user accounts. The new PC doesn't have multiple user accounts, so I wondered if this might be something to do with it?

I can provide copies of the two Profiles folders but the original is quite big!

Thanks in advance, Simon

The solution of physically copying the Profiles folder seems to be officially endorsed by Mozilla but when I tried it, FF failed to start up displaying an error message that it could not find my profile and closing. I am trying to set up a new PC for my wife's exclusive use, so the Profiles folder in question was from a shared PC with both of us having our own user accounts. The new PC doesn't have multiple user accounts, so I wondered if this might be something to do with it? I can provide copies of the two Profiles folders but the original is quite big! Thanks in advance, Simon

All Replies (3)

more options

Firefox uses the profiles.ini file to register the profiles, so you need to copy this file as well or use the Profile Manager to create a new profile and use the "Choose Folder" button to select this profile.

more options

You can copy certain files with Firefox closed to the current profile folder to transfer or recover personal data. Note that best is to avoid copying a full profile folder.

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;32+) and key4.db (decryption key;58+) for Passwords saved in the Password Manager
    key3.db support ended in 73+; to use key3.db in 58-72, make sure to remove key4.db
  • cert9.db (58+) for (intermediate) 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)
more options

Thanks for the advice and the helpful links but copying the Profiles.ini made no difference "Your profile cannot be found etc". I tried using the profiles manager to create a new one using the instructions but that just left me with a default profile i.e. like a fresh install. I will see what else your other reply offers.