Hi, I'm not sure what you lost. Was it your browsing history (list of URLs you visited)?

Firefox does not keep a backup of your browsing history, so if it was cleared, there is no built-in way to restore it.

Oh, if you mean audio volume, does your Volume Mixer show that Firefox is sending audio output to the system. I'm not sure about your version of Windows, but try right-clicking the speaker icon on the right end of the Windows Taskbar, and click Open Volume Mixer. When Window is receiving audio from Firefox, the Firefox bar should be moving.

Sometimes when Firefox is sending audio but it isn't audible, this is caused by Firefox directing audio to a device that is disconnected or turned off. For example, some users mentioned a problem with headphones/headsets that were not currently attached.

hi, my issue is I've lost all sound volume. Nothing has sound, youtube, movies, ect ect. No sound whatsoever. Thanks ...

ty Jsher ... you were great help.  :-)