Greetings, to my surprise, my one month old MBP late-2011 base 15" just acted nuts. It started by not letting me enter the backgrounds settings, so I decided to reboot. After the boot Finder would not start up. The top line was gone, and I could not open any programs. I got errors constantly. Aswell, on bootup it has always made this whirring sound from the HDD, is that normal? Keep in mind this is my first Mac ever.