how to eliminate all bookmarks on one computer before turning on sync on another computer with desired bookmarks?

If you're absolutely sure you don't care about the bookmarks on your laptop: # Click on the hamburger menu (the button with three horizontal bars in the upper-right). # Choose "Library", then "bookmarks", then "show all bookmarks". # In the sidebar on the left-hand side, you'll see a list of all of your bookmark folders, underneath the heading "all bookmarks". Click on the first one you see. # Click anywhere on the list of bookmarks, and press ctrl+a to select all of them. # Right-click on them, and choose "delete". # Repeat this process for each bookmarks folder. Then sign into sync on both computers. If you think there's any possibility you'll need the bookmarks on your laptop in the future, it's a good idea to make a backup of your profile folder before doing this. [[Back up and restore information in Firefox profiles|This article]] has directions on how to do that.