Hello yall. I am new to Mac. Got me a nice new 2.8 24 incher. Only problem is, all of a sudden, OSX decided to freeze on me. I have tried turning the computer off and on, and even unplugging it for a bit. The computer boot up, but I cannot click on anything. The menus up top do not respond when clicked upon, nor does any of my items in the dock. When left sitting, the screensaver activates. What can i do here?