Mozilla Firefox and Google Chrome are two completely separate browsers, different computer programs, which are installed separately. If you have installed Google Chrome, can you find its icon on the desktop? I'm sure your son is familiar with it (circle with red, green, and yellow segments on the outside and a blue dot in the center). If the computer you are currently using doesn't have Google Chrome, you can visit its product page here: http://www.google.com/chrome/ You can start up each browser independently, or simultaneously, and switch between them to do what you prefer in each one. Of course, if your computer does not have a lot of memory installed, doing a lot in both at the same time will bog things down...