Transferring book marks from saved user folder

My staff is getting new machines, running Windows 10, that are replacing their old machines, which ran Windows 7. I have copied their old user files onto the new machines. These old files include their saved favorites from their browsers, and these are accessible directly through Windows, but they are not appearing in their browsers. Their bookmarks are not appearing in their browsers at all, although they do appear in places like (for Chrome) C:Users{username}AppDataGoogleChromeUser DataDefaultBookmarks (no file extension).

How do I make the favorites and bookmarks appear in the browsers again?