Hi navnyu.

You have probably made Firefox Refresh. Your bookmarks and password should stay untouched, only add-ons and some settings are removed. Please read the KB article linked - in the bottom is the created folder mentioned as well as how to recover your old data from it.

whr is the kb article ..and thr is one folder as i said previously .i tried copying and pasting the entire folder content into thr program files/mozilla firefox folder ..but nothing happens ..same old firefox opnes ..

please help ..there is a reason why old firefox data folder has been made on desktop ..so that one can restore ..but how ..please help ..what article you were talking about ..where can i find that one .

The KB article is here - the same as linked above.

When you Refresh/Reset Firefox then a new profile is created and some personal data (bookmarks, history, cookies, passwords, form data) is automatically imported. The current profile folder will be moved to an "Old Firefox Data" folder on the desktop. Installed extensions and other customizations (toolbars, prefs) that you have made are lost and need to be redone.

It is possible to recover data from the "Old Firefox Data" folder on the desktop, but be cautious not to copy corrupted files to avoid carrying over problems.

You can use this button to go to the current Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox

You can copy files like these to the current Firefox profile folder to recover specific data.

• bookmarks and history: places.sqlite
• bookmark backups: JSON backups in the bookmarkbackups folder
• SQLite files like cookies.sqlite (cookies) and formhistory.sqlite (saved form data)
• logins.json and key3.db (decryption key) for Passwords saved in the Password Manager
• cert8.db for stored intermediate certificates (Certificate Manager)
• persdict.dat for words you added to the spelling checker dictionary
• permissions.sqlite and possibly content-prefs.sqlite for Permissions and Site Preferences
• sessionstore.js for open tabs and pinned tabs and tab groups

• https://support.mozilla.org/kb/Recovering+important+data+from+an+old+profile
• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox