Hi qwigoqwaga, did you end up seeing any of the data that you copied over reflected in the new profile, or none of it, just the install defaults?

If you don't see anything, I suspect the file replacement didn't work.

Make sure you are viewing hidden files and folders: https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files

Now, let's say you have this current profile folder -- obviously I don't know the real name:

C:\Users\your_user_name\AppData\Roaming\Mozilla\Firefox\Profiles\z43yx2w1.default

And you have a backup of your old profile folder whose name I also don't know:

[some location]\a1b23cd4.default

If you were to replace the places.sqlite file in the current profile folder with the places.sqlite file from your backup, that should give you the bookmarks and history of the old profile when you start Firefox with the new profile.

Does that work? Please make sure Firefox is closed when replacing data files or wacky things may happen.

If I change it to show hidden files and folders, can I not just replace everything again? Or should I just replace the places.sqlite?

You can replace everything if you like. Places.sqlite is just a very obvious file to test.

I tried recopying everything and then recopying places.sqlite but neither of those worked.

You do not see any evidence of earlier settings or data? It sounds as though Firefox is not using the profile folder you are modifying. The internal page about:profiles lists all profile folders that Firefox is aware of. The current profile is marked "This is the profile in use and it cannot be deleted." Are there others on the page? If so, you can click "Set as default profile" and then exit/restart Firefox to try that on.

Note: the important data goes in the "Root Directory" which is under AppData\Roaming.

There's the default profile and one I created, both only list this as both the root and local folders and neither profile has my settings working: C:\Users\Name\AppData\Roaming\Mozilla\Firefox\Profiles\su6uok13.default

If you click the "Open Folder" button for that profile and then double-click into the bookmarkbackups folder, does it show the bookmark backup files you copied in? If they are here, you should be able to restore one of them from the Restore menu described in the following article: Restore bookmarks from backup or move them to another computer.

That does appear to have restored some of my history (when I type in the search bar, sites I've never been to on this computer but have visited before pop up), but it doesn't seem to have restored my bookmarks. The most recent backup file is from 2015 so I'm not sure I even have my most recent backup. What I really need are my saved logins.

If I were to create a firefox account where you sign in on my other computer that has all my settings, would it save those settings to that account and then I could just sign in with that on the new computer?

If you want to try Sync, you can, I absolutely cannot predict the results.

For saved logins:

Are both Firefoxes on version 63? There was a change at some point from "key3.db" to "key4.db", the companion file which lets Firefox read a copied in logins.json file. Any mismatch can cause Firefox to discard the old file. This is why when I describe the best way to transplant a profile backup, I suggest creating a new profile, removing all contents from its folder, and putting in all the contents of the old folder.

I'm not sure. I think what I'll try is save a backup now and then try to copy in those files since both versions of firefox should be the same up to date version.

Creating a new up to date backup seems to have worked. Thank you for your help!