I just bought a new Raspberry Pi 3 and a pre-loaded sd card with Raspbian. I turned the Pi on and I'm not sure if the raspbian is installed. I didn't have any window to choose an option to install. Like in all the guides show. I do see the Pi logo at the center of the screen, and a toolbar at the top, including some web browser.
Should I download NOOBS and install it, or is Raspbian is already installed?