On both Windows 8.1 and Windows 10, Firefox stores bookmarks locally. So bookmarks are able to be backed up by Backblaze.
1. To restore your bookmarks, first, navigate to the "View/Restore Files" Page of your account:
2. Once there, scroll to the bottom of the page where you will see a pane showing all the files and folders that have backed up to us, at the top of the pane make sure to check the box next "show hidden files"
3. Expand folders using the following path:
C:\Users\<your Windows login username>\AppData\Roaming\Mozilla\Firefox\Profiles\<Profile folder>\
4. Select the folder named "Bookmarkbackup" and then click on "Continue with Restore"
5. Once the Restore is ready and downloaded, unzip the "Bookmarkbackup" folder onto your computer, open the folder, and copy the desired recovery file
(please note that you can use the dates noted in the file names to determine which recovery file you wish to use)
6. Locate this same folder on the computer itself, and paste the recovery file into it.
7. Open your Firefox Browser and click the Library button on the toolbar
(if the library button does not appear, click the menu button instead, and select "Library" from there )
8. Click Bookmarks, and then click the "Show All Bookmarks" option at the bottom
9. In the Pop-up window, click "Import and Backup" and then mouse over "Restore" in the drop-down menu and select the desired data.