The most visited "smart folder" queries your history, so to get those same results on the new system, you would need to copy over the database file that stores your history and bookmarks, named places.sqlite, and replace the empty one on your Windows 10 system. Note: if you have created new bookmarks on the Windows 10 Firefox that you need to save, please export them first using the method in this article: [[Export Firefox bookmarks to an HTML file to back up or transfer bookmarks]] On your Windows 10 system, open your currently active profile folder using either: * "3-bar" menu button > "?" button > Troubleshooting Information * (menu bar) Help > Troubleshooting Information * type or paste about:support in the address bar and press Enter In the first table on the page, click the "Show Folder" button. This should launch a new window listing various files and folders in Windows Explorer. Leaving that window open, switch back to Firefox and Exit, either: * "3-bar" menu button > "power" button * (menu bar) File > Exit Pause while Firefox finishes its cleanup, then rename '''places.sqlite''' to something like OLDplaces.sqlite. There may be some similarly named temp files such as places.sqlite-wal which you can just delete. This will avoid Firefox trying to merge those into your old file and corrupting everything. Then drop your old places.sqlite file into this folder. When you start Firefox back up again, your old bookmarks and history should appear. Does it work? ''Note:'' By default, Windows hides some file extensions. If you do not see the .sqlite file extension, it may show up as the file type. To show all extensions, which greatly eases the process of confirming the identity of files and renaming them, please see either/both of these Microsoft support articles: * https://support.microsoft.com/en-us/kb/865219 * http://windows.microsoft.com/en-us/windows/show-hide-file-name-extensions (I haven't look for a Windows 10 version)