My Firefox browser was "taken over" by Yahoo - I had no access to Firefox at all. I was able to restore the Firefox, but lost all my bookmarks. Can you restore

Did you uninstall Firefox and also removed your personal data? When you remove personal data when uninstalling Firefox then all profile folders with your personal data including the bookmarks have been removed. You would need an undelete utility if you do not have a backup. *Recuva: http://www.piriform.com/recuva *https://support.mozilla.org/kb/Recovering+important+data+from+an+old+profile *http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox