Diễn đàn hỗ trợ Firefox

Why can't I change the volume in one tab? During a meeting, for example, the radio is on, and it is much louder than the meeting, and you cannot adjust the volume of a single tab. This is very bothersome, not only in the above case. These pages determine the volume themselves. Some have regulations on the site, but not always. I am very tired of this problem. Are there any ways to change the volume of a given tab?

1. I'm using Firefox portable latest version.

Nearly all addons stop working every time I restart Firefox. I have to manually disable and re-enable each addon to make them working again.

It takes considerably long time the first time I load the first website after I restart Firefox. Also it may suddenly hang after using for a long time.

What's up? How could I fix them?

2. I would like to transfer all settings, cookies/local storage, addons (settings and files etc.) to a fresh copy of Firefox portable, to see if those issues would be fixed. What should I do? Which files do I need to backup?

Thank you.