Firefox stores user data in the profile folder, this is not in the same location as the Firefox program. Did you copy the profile folder? If you just copied the installation directory containing the Firefox program you would have lost the bookmarks. For details of the location of the profile folder see http://kb.mozillazine.org/Profile_folder_-_Firefox If you did copy the profile folder, this link shows you what files you can recover - https://support.mozilla.com/kb/Recovering+important+data+from+an+old+profile