I'm not exactly clueless, but I'm not an engineer. For some reason, I had three open Firefox/Mozilla browsers open on the taskbar but connected to one icon. Today, I've lost the browser with all of my frequently used sites, and tons of research, family, friends, World War II, finances, etc. The other two browsers had one tab, and maybe ten-fifteen tabs, respectively. How do I restore the main browser? Thank you for any assistance.