Did the Microsoft person have you save your old data? That option typically creates a folder named:

C:\Windows.old

If you find that folder:

Set Windows to show hidden files and folders -- this Microsoft article has the steps:

https://support.microsoft.com/en-us/windows/view-hidden-files-and-folders-in-windows-97fbc472-c603-9d90-91d0-1166d1d9f4b5

Then explore that folder up to this point (if it exists):

C:\Windows.old\Users\<username>\AppData\Roaming\Mozilla\Firefox\Profiles\

If you find recent data there, please pause and we can suggest how to grab your last bookmark backup.

Thanks for replying. I’m afraid I made it sound like a Microsoft person was involved, but that is not the case. What happened was, upon turning on the computer I got a window that said something like Windows did not (here I don’t remember the exact wording) open or something like that. And “it” gave me some options (can’t remember them clearly) and I chose to have Windows 10 redownloaded and then installed while saving my files, but would lose all apps. I don’t think it offered the chance to save anything in a special folder or I would have done that. Hope this helps

If it was supposed to save all your files, the two possibilities are:

(A) They are in their original locations (B) They are in the Windows.old folder

If you go into Windows File Explorer and check your C drive, do you have a Windows.old folder?

Yes I have a Windows.old folder. In it are two folders: Users and WINDOWS

Firefox uses two locations in the hidden AppData location for the Firefox profile folder. Location used for the main profile that keeps your personal data.

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

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.

• 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)

As a footnote to cor-el's reply, this was the old location before the reinstall --

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

-- and that folder was moved to:

C:\Windows.old\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>

If you drill down in that folder -- as I mentioned earlier, set Windows to show hidden files and folders per

https://support.microsoft.com/en-us/windows/view-hidden-files-and-folders-in-windows-97fbc472-c603-9d90-91d0-1166d1d9f4b5

-- can you eventually come to a folder named bookmarkbackups?

Firefox can use those files to replace your current (new) set of bookmarks with the set in the backup file. I suggest copying one or two recent backups to your Windows desktop for easier access. Then check the steps in this article:

Restore bookmarks from backup or move them to another computer

When you expand the Restore menu, you'll need to use "Choose File" to point Firefox to your desktop where you pasted the backup files.

Success?

You can look at this tool to inspect a compressed jsonlz4 bookmarks backup and possibly convert this file to HTML to be able to import/merge bookmarks.

• https://www.jeffersonscher.com/res/bookbackreader.html

Thanks so much, jscher2000, "it" worked. I found "bookmarkbackups" as per your instructions. Then using the restore function in Manage bookmarks went back into the "bookmarkbackups" file to choose the last backup listed and the restore worked! Pretty cool!

Great news, and thank you for reporting back.

The C:\Windows.old folder is only retained for 28 days, so you might want to back up other data from it now before time gets away from you.