why is my view panel slightly larger than my screen size?

What follows is not a new issue. I remember having to deal with it when I first purchased my mac snow leopard a couple of years ago, but I forgot how I resolved it. It was a simple fix, this I do remember.

My problem, once again, is that I need to make everything fit into the size of my screen, so I don't have to move the arrow right, left, up or down to see the margins of my view panel. This problem also applies to my dashboard as well.