You can check this: *https://support.mozilla.org/en-US/kb/recover-user-data-missing-after-firefox-update Note that you should be cautious with using System Restore as that can cause your Firefox installation to get corrupted because only white-listed files are restored. *always be cautious with using System Restore. *you may lose data in the Firefox profile folder like .js and .ini files *You may have to reinstall affected software