On Windows XP you can find the Firefox profile folder in this location: *C:\Documents and Settings\<user>\Application Data\Mozilla\Firefox\Profiles\<profile>\ The "AppData" folder in Windows Vista and later Window 7+ versions and the "Application Data" folder in XP/Win2K are hidden folders. *http://kb.mozillazine.org/Show_hidden_files_and_folders ---- You can copy files that store specific data that you want to restore to the current profile folder with Firefox closed. You can use this button to go to the currently used Firefox profile folder: *Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder) *http://kb.mozillazine.org/Profile_folder_-_Firefox For the bookmarks that would be places.sqlite or if there is a problem with this file then restore a compressed .jsonlz4 backup in the bookmarkbackups folder. See: *https://support.mozilla.org/kb/Recovering+important+data+from+an+old+profile *http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox *https://support.mozilla.org/kb/restore-bookmarks-from-backup-or-move-them