please see attached photo ... i have tried everything to install it .. restarted my computer opened closed the program, and nothing still worked ..
please could you open a new finder window and navigate to your applications folder.
Have the other finder window next to the new one (the one in your screen shot).
Drag the application icon into the applications folder in the new finder window.
Hope that works.
I had the same problem, but Matthew's approach has solved it (remember that you might need to change the security and privacy setting to allow apps to be installed from "Anywhere", not just from the App Store, which is the default setting if you are using Mountain Lion).