I just installed photoshop after having my computer reformatted, and now when I try to do something to a picture, nothing works. For instance, I am trying to use the clone tool and when i try to click on the air I want to manipulate, nothing happens (I am holding alt and then clicking, then clicking the area I want to change). Also, the brush tool does nothing. I think that it is probably some setting I have that won't allow me to use any of these tools, but I don't really know. Any help would be much appreciated, thanks.