Hi,
When you uninstall the firefox, it creates old firefox folder in your desktop. You could click on that and see the profile has any js.bak on the above subject in the link. If you check the properties, and found that it does contain more than 0 bytes, see the date of it, if you think that it contains the old data like your preference, saved passwords, then you could use that profile to restore the session . I will try to give the link in this regard after locating it in the web