Hi lvirgil, which steps are you following?

Also, I'm not sure how you can see a file that's on your old computer when it's inaccessible? If you mean you have remote access but not physical access, you could try copying file(s) to an intermediary location in the cloud, such as your Microsoft OneDrive (non-shared folder, of course) associated with your Windows 10 account, as a way to get them available to the second computer.

If you haven't used Sync on the old computer then the only way to transfer personal data like the bookmarks is to copy files from that computer to your current computer.

You would need a backup of the bookmarks, either a JSON backup from the bookmarkbackups folder or a backup (HTML or JSON) that you created yourself.

See also "Tips and tricks":

• https://support.mozilla.org/kb/how-do-i-use-bookmarks

• https://support.mozilla.org/kb/Recovering+important+data+from+an+old+profile
• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

You can copy files like these to the current Firefox profile folder to recover/trahnfer specific data.

• bookmarks and history: places.sqlite
• bookmark backups: JSON backups in the bookmarkbackups folder
• SQLite files like cookies.sqlite (cookies) and formhistory.sqlite (saved form data)
• logins.json and key3.db (decryption key) for Passwords saved in the Password Manager
• cert8.db and possibly cert_override.txt for (intermediate) certificates stored in the Certificate Manager
• persdict.dat for words you added to the spelling checker dictionary
• permissions.sqlite for Permissions and possibly content-prefs.sqlite for other Site Preferences
• sessionstore.js for open tabs and pinned tabs and tab groups